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Chemistry The Science in Context

Thomas R. Gilbert

Chapter 3

Stoichiometry: Mass, Formulas, and Reactions - all with Video Answers

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Chapter Questions

03:39

Problem 1

Each of the pairs of containers pictured in Figure P3.1 contains substances composed of elements X (red spheres) and $Y$ (blue spheres). For each pair, write a balanced chemical equation describing the reaction that takes place. Be sure to indicate the physical states of the reactants and products, using the appropriate symbols in parentheses.
(FIGURES CANT COPY)

Joanna Josey
Joanna Josey
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03:28

Problem 2

Identify the limiting reactant in each of the pairs of containers pictured in Figure P3.2. The red spheres represent atoms of element $\mathrm{X}$, and the blue spheres represent atoms of element Y. Each question mark means that there is unreacted reactant left over.
(FIGURES CANT COPY)

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:02

Problem 3

Which of the drawings in Figure $\mathrm{P} 3.3$ best illustrates the $100 \%$ reaction between $\mathrm{N}_{2}$ and $\mathrm{O}_{2}$ to produce $\mathrm{N}_{2}$ O? The red spheres represent atoms of oxygen and the blue spheres represent atoms of nitrogen.
(FIGURE CANT COPY)

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:48

Problem 4

Is there a limiting reactant in any of the reactions depicted in Figure $\mathrm{P} 3.3 ?$ If so, what is it, and how much of the excess reactant remains?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:29

Problem 5

Which of the molecules in Figure $P 3.5$ have the same empirical formulas?
(FIGURES CANT COPY)

Sam Limsuwannarot
Sam Limsuwannarot
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02:18

Problem 6

Which of the drawings in Figure $\mathrm{P} 3.6$ represent balanced chemical equations? Write balanced chemical equations for any unbalanced equations in Figure $\mathrm{P} 3.6 .$ The red spheres represent oxygen, black represent carbon, blue represent nitrogen, and yellow represent sulfur.
(FIGURES CANT COPY)

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:40

Problem 7

The two major products of combustion are $\mathrm{CO}_{2}$ and $\mathrm{H}_{2} \mathrm{O}$ Figure $P 3.7$ shows two mass spectra. Which belongs to water, and which belongs to carbon dioxide?
(FIGURES CANT COPY)

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
03:10

Problem 8

Figure $P 3.8$ shows the mass spectrum of a simple hydrocarbon that can be combusted as a fuel. What is the molecular formula of this hydrocarbon?
(FIGURE CANT COPY)

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:35

Problem 9

What is the percent yield of $\mathrm{NH}_{3}$ for the reaction depicted in Figure P3.9? The blue spheres represent nitrogen, and the white spheres are hydrogen.
(FIGURES CANT COPY)

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
03:07

Problem 10

Use representations $[\mathrm{A}]$ through $[\mathrm{I}]$ in Figure $\mathrm{P} 3.10$ to answer questions a-f.
a. Which two compounds have the same empirical formula?
b. Which compound has a molecular mass of 180 amu?
c. Which compound might have a molar mass of $180 \mathrm{g} ?$
d. Which compound has the largest percent oxygen by mass?
e. The mass of one gold bar in [D] is 12.4 kg. The mass of one silver bar in $[\mathrm{E}]$ is $31 \mathrm{kg} .$ Which contains more atoms - the gold bar or the silver bar?
f. When completely combusted, which compound will produce more moles of carbon dioxide- -benzene [A] or table sugar [C]?
(IMAGES CAN'T COPY)

Sam Limsuwannarot
Sam Limsuwannarot
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00:25

Problem 11

In a combination reaction, is the number of different products equal to, less than, or greater than the number of different reactants?

Sam Limsuwannarot
Sam Limsuwannarot
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00:49

Problem 12

On the basis of the compositions and physical states of Earth's various layers (Figure 3.3 ), which of the following substances has the higher melting point: $\mathrm{Al}_{2} \mathrm{O}_{3}$ or $\mathrm{Ni}$ ?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:00

Problem 13

On the basis of the distribution of the elements in Earth's layers (see Figure $3.3),$ which of the following substances should be the most dense? (a) $\mathrm{SiO}_{2}(s) ;$ (b) $\mathrm{Al}_{2} \mathrm{O}_{3}(s) ;$ (c) $\mathrm{Fe}(\ell)$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:26

Problem 14

The proportions of the elements that make up the asteroid 433 Eros are similar to those that make up Earth. Scientists believe that this similarity means that 433 Eros and Earth formed around the same time. If another asteroid formed after Earth formed a solid crust, and if this asteroid was the product of a collision between Earth and an even larger asteroid, how would the new asteroid's composition differ from that of 433 Eros?

Zachary Warner
Zachary Warner
Numerade Educator
01:06

Problem 15

In principle we could use the more familiar unit dozen in place of mole when expressing the quantities of particles (atoms, ions, or molecules) in chemical reactions. What would be the disadvantage in doing so?

Sam Limsuwannarot
Sam Limsuwannarot
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00:58

Problem 16

In what way are the molar mass of an ionic compound and its formula mass the same, and in what ways are they different?

Sam Limsuwannarot
Sam Limsuwannarot
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00:36

Problem 17

Do molecular compounds containing three atoms per molecule always have a molar mass greater than that of molecular compounds containing two atoms per molecule? Explain.

Sam Limsuwannarot
Sam Limsuwannarot
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Problem 18

Without calculating their molar masses (though you may consult the periodic table), predict which of the following oxides of nitrogen has the larger molar mass: $\mathrm{NO}_{2}$ or $\mathrm{N}_{2} \mathrm{O}$.

Angela Williamson
Angela Williamson
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02:55

Problem 19

Earth's atmosphere contains many volatile substances that are present in trace amounts. The following quantities of these trace gases were found in a $1.0 \mathrm{mL}$ sample of air. Calculate the number of moles of each gas in the sample.
a. $4.4 \times 10^{14}$ atoms of $\mathrm{Ne}(g)$
b. $4.2 \times 10^{13}$ molecules of $\mathrm{CH}_{4}(g)$
c. $2.5 \times 10^{12}$ molecules of $\mathrm{O}_{3}(g)$
d. $4.9 \times 10^{9}$ molecules of $\mathrm{NO}_{2}(g)$

Ronald Prasad
Ronald Prasad
Numerade Educator
03:36

Problem 20

The following quantities of trace gases were found in a 1.0 mL sample of air. Calculate the number of moles of each compound in the sample.
a. $1.4 \times 10^{13}$ molecules of $\mathrm{H}_{2}(g)$
b. $1.5 \times 10^{14}$ atoms of $\mathrm{He}(g)$
c. $7.7 \times 10^{12}$ molecules of $\mathrm{N}_{2} \mathrm{O}(g)$
d. $3.0 \times 10^{12}$ molecules of $\mathrm{CO}(g)$

Jennifer Hudspeth
Jennifer Hudspeth
Numerade Educator
07:39

Problem 21

How many atoms of titanium are there in 0.125 mole of each of the following?
a. ilmenite, $\mathrm{FeTiO}_{3}$
b. titanium(IV) chloride
c. $\mathrm{Ti}_{2} \mathrm{O}_{3}$
d. $T i_{3} O_{5}$

Lori Mccoy
Lori Mccoy
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Problem 22

How many atoms of iron are there in 2.5 moles of each of the following?
a. wolframite, FeWO $_{4}$
b. pyrite, $\mathrm{FeS}_{2}$
c. magnetite, $\mathrm{Fe}_{3} \mathrm{O}_{4}$
d. hematite, $\mathrm{Fe}_{2} \mathrm{O}_{3}$

Audrey Fleming
Audrey Fleming
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03:11

Problem 23

Which substance in each of the following pairs of quantities contains more moles of sulfur?
a. 3 moles of $\mathrm{Al}_{2} \mathrm{S}_{3}$ or 4 moles of $\mathrm{Fe}_{2} \mathrm{S}_{3}$
b. 3 moles of $\mathrm{Li}_{2} \mathrm{SO}_{4}$ or 4 moles of $\mathrm{CaS}$
c. 2 moles of $\mathrm{SO}_{3}$ or 2 moles of $\mathrm{SO}_{2}$

Jennifer Hudspeth
Jennifer Hudspeth
Numerade Educator
00:54

Problem 24

Which substance in each of the following pairs of quantities contains more moles of nitrogen?
a. 2 moles of $\mathrm{Li}_{3} \mathrm{N}$ or 0.5 mole of $\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}$.
b. 1 mole of $\mathrm{NO}$ or 0.4 mole of $\mathrm{NO}_{2}$.
c. 3 moles of $\mathrm{NF}_{3}$ or 1 mole of $\mathrm{N}_{2} \mathrm{O}_{5}$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:53

Problem 25

Elemental Composition of Amino Acids Carbon, hydrogen, nitrogen, and oxygen are the most prevalent components of amino acids, the fundamental building blocks of proteins in living systems. How many moles of oxygen are in 1.50 mol of the following compounds?
a. Glycine, the smallest amino acid: $C_{2} H_{5} N O_{2}$
b. Lysine, essential in the diet of humans: $C_{6} \mathrm{H}_{14} \mathrm{N}_{2} \mathrm{O}_{2}$
c. Asparagine, produced in our bodies: $C_{4} H_{8} N_{2} O_{3}$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:38

Problem 26

Composition of Uranium Ores The uranium used for nuclear fuel exists in nature in several minerals. Calculate how many moles of uranium are in 1 mole of the following:
a. carnotite, $\mathrm{K}_{2}\left(\mathrm{UO}_{2}\right)_{2}\left(\mathrm{VO}_{4}\right)_{2}$.
b. uranophane, $\mathrm{CaU}_{2} \mathrm{Si}_{2} \mathrm{O}_{11}$.
c. autunite, $\mathrm{Ca}\left(\mathrm{UO}_{2}\right)_{2}\left(\mathrm{PO}_{4}\right)_{2}$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:19

Problem 27

How many moles of carbon are there in $500.0 \mathrm{g}$ of carbon?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:37

Problem 28

How many moles of gold are there in 2.00 ounces of gold?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:19

Problem 29

Cancer Therapy with Iridium Metal When iridium-192 is used in cancer treatment, a small cylindrical piece of $^{192} \mathrm{I}$, $0.6 \mathrm{mm}$ in diameter and $3.5 \mathrm{mm}$ long, is surgically inserted into the tumor. If the density of iridium is $22.42 \mathrm{g} / \mathrm{cm}^{3},$ how many iridium
atoms in the sample?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
05:33

Problem 30

Gold Nanoparticles The product shown i Figure $P 3.30$ contains gold nanoparticles in water. The manufacturer claims that drinking this beverage improves human health. How many gold atoms are in a gold nanoparticle with a diameter of $2.00 \mathrm{nm}(d=19.3 \mathrm{g} / \mathrm{mL}$ $\left.1 \mathrm{amu}=1.66054 \times 10^{-24} \mathrm{g}\right) ?$.
(IMAGE CAN'T COPY)

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
02:00

Problem 31

How many moles of iron are there in 1 mole of the following compounds? (a). $\mathrm{FeO} ;$ (b) .$\mathrm{Fe}_{2} \mathrm{O}_{3} ;$ (c) $\mathrm{Fe}(\mathrm{OH})_{3}$ (d). $\mathrm{Fe}_{3} \mathrm{O}_{4}$

Nishant Kumar
Nishant Kumar
Numerade Educator
00:24

Problem 32

How many moles of sodium are there in 1 mole of the following compounds? (a) $\mathrm{NaCl} ;$ (b) .$\mathrm{Na}_{2} \mathrm{SO}_{4} ;(\mathrm{c}) \mathrm{Na}_{3} \mathrm{PO}_{4}$.(d) $\mathrm{NaNO}_{3}$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:55

Problem 33

Calculate the molar masses of the following atmospheric molecules: $(\mathrm{a}) \mathrm{SO}_{2} ;(\mathrm{b}) \mathrm{O}_{3} ;(\mathrm{c}) \mathrm{CO}_{2} ;(\mathrm{d}) \mathrm{N}_{2} \mathrm{O}_{5}$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:31

Problem 34

Determine the molar masses of the following minerals:
a. rhodonite, $\mathrm{MnSiO}_{3}$
b. scheelite, CaWO $_{4}$
c. ilmenite, FeTiO $_{3}$
d. magnesite, $\mathrm{Mg} \mathrm{CO}_{3}$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:46

Problem 35

Calculate the molar masses of the following common flavors in food:
a. vanillin, $\mathrm{C}_{8} \mathrm{H}_{8} \mathrm{O}_{3}$.
b. oil of cloves, $\mathrm{C}_{10} \mathrm{H}_{12} \mathrm{O}_{2}$.
c. anise oil, $\mathrm{C}_{10} \mathrm{H}_{12} \mathrm{O}$.
d. oil of cinnamon, $\mathrm{C}_{9} \mathrm{H}_{8} \mathrm{O}$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:18

Problem 36

Calculate the molar masses of the following common sweeteners:.
a. sucrose, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$.
b. saccharin, $\mathrm{C}_{7} \mathrm{H}_{5} \mathrm{NO}_{3} \mathrm{S}$.
c. aspartame, $\mathrm{C}_{14} \mathrm{H}_{18} \mathrm{N}_{2} \mathrm{O}_{5}$.
d. fructose, $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:29

Problem 37

Suppose pairs of balloons are filled with $10.0 \mathrm{g}$ of the following pairs of gases. Which balloon in each pair has the greater number of particles? (a) $\mathrm{CO}_{2}$ or $\mathrm{NO} ;$ (b) $\mathrm{CO}_{2}$ or $\mathrm{SO}_{2} ;(\mathrm{c}) \mathrm{O}_{2}$ or $\mathrm{Ar}$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:53

Problem 38

If you had equal masses of the substances in the following pairs of compounds, which of the two would contain the greater number of ions? (a) NaBr or $\mathrm{KCl} ;$ (b) $\mathrm{NaCl}$ or $\mathrm{MgCl}_{2} ;$ (c) $\mathrm{BaCl}_{2}$ or $\mathrm{Li}_{2} \mathrm{CO}_{3}$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:21

Problem 39

How many moles of $\mathrm{SiO}_{2}$ are there in a quartz crystal $\left(\mathrm{Si} \mathrm{O}_{2}\right)$ that has a mass of $45.2 \mathrm{g} ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:51

Problem 40

How many moles of $\mathrm{NaCl}$ are there in a crystal of halite that has a mass of $6.82 \mathrm{g} ?$.

Ronald Prasad
Ronald Prasad
Numerade Educator
00:38

Problem 41

What is the mass of 0.122 mol $\mathrm{Mg} \mathrm{CO}_{3} ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
02:33

Problem 42

What is the volume of 1.00 mol benzene $\left(\mathrm{C}_{6} \mathrm{H}_{6}\right)$ at $20^{\circ} \mathrm{C} ?$ The density of benzene is $0.879 \mathrm{g} / \mathrm{mL}$.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
10:02

Problem 43

The density of uranium $\left(\mathrm{U} ; 19.05 \mathrm{g} / \mathrm{cm}^{3}\right)$ is more than five times as great as that of diamond $\left(\mathrm{C} ; 3.514 \mathrm{g} / \mathrm{cm}^{3}\right) .$ If you have a cube ( $1 \mathrm{cm}$ on a side) of each element, which cube.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
06:22

Problem 44

Aluminum $(d=2.70 \mathrm{g} / \mathrm{mL})$ and strontium $(d=2.64 \mathrm{g} / \mathrm{mL})$
have nearly the same density. If we manufacture two cubes, each containing 1 mole of one element or the other, which cube will be smaller? What are the dimensions of this cube?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
00:44

Problem 45

In a balanced chemical equation, does the number of moles of reactants always equal the number of moles of products?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:25

Problem 46

In a balanced chemical equation, does the sum of the coefficients for the reactants always equal the sum of the coefficients for the products?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:40

Problem 47

In a balanced chemical equation, must the sum of the masses of all the gaseous reactants always equal the sum of the masses of the gaseous products?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
05:14

Problem 48

In a balanced chemical equation, must the sum of the volumes occupied by the gaseous reactants always equal the sum of the volumes occupied by the gaseous products?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
03:52

Problem 49

Using different-colored spheres to represent $\mathrm{C}$ and $\mathrm{O}$ sketch the reaction between five C atoms and the necessary number of $\mathrm{O}_{2}$ molecules to produce a $50 \%$ mixture of $\mathrm{CO}$ and $\mathrm{CO}_{2}$.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
02:53

Problem 50

Using different-colored spheres to represent $\mathrm{N}$ and $\mathrm{O}$ sketch the reaction between three molecules of $\mathrm{N}_{2}$ and sufficient $\mathrm{O}_{2}$ to produce a mixture containing $50 \% \mathrm{NO}_{2}$ and $50 \% \mathrm{N}_{2} \mathrm{O}_{4}$.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
00:46

Problem 51

Fluorine is a very reactive, dangerous element, as can be seen in the following unbalanced equation:
$$\mathrm{F}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(\ell) \rightarrow \mathrm{HF}(a q)+\mathrm{O}_{2}(g)$$
After balancing this chemical equation, what is the coefficient of HF?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:32

Problem 52

Aluminum reacts with elemental oxygen at high temperatures to give pure aluminum oxide. What is the coefficient of $\mathrm{O}_{2}(\mathrm{g})$ in the balanced chemical equation?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
05:58

Problem 53

Balance the following chemical reactions, which contribute to weathering of the iron-silicate minerals ferrosilite (FeSiO $_{3}$ ), fayalite $\left(\mathrm{Fe}_{2} \mathrm{SiO}_{4}\right),$ and greenalite $\left[\mathrm{Fe}_{3} \mathrm{Si}_{2} \mathrm{O}_{5}(\mathrm{OH})_{4}\right]:$
a. $\operatorname{FeSiO}_{3}(s)+\mathrm{H}_{2} \mathrm{O}(\ell) \rightarrow \mathrm{Fe}_{3} \mathrm{Si}_{2} \mathrm{O}_{5}(\mathrm{OH})_{4}(s)+\mathrm{H}_{4} \mathrm{SiO}_{4}(a q)$.
b. $\mathrm{Fe}_{2} \mathrm{SiO}_{4}(s)+\mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(\ell) \rightarrow$
$\mathrm{FeCO}_{3}(s)+\mathrm{H}_{4} \mathrm{SiO}_{4}(a q)$.
c. $\mathrm{Fe}_{3} \mathrm{Si}_{2} \mathrm{O}_{5}(\mathrm{OH})_{4}(s)+\mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(\ell) \rightarrow$.
$\mathrm{FeCO}_{3}(s)+\mathrm{H}_{4} \mathrm{SiO}_{4}(a q)$.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
08:08

Problem 54

Some scientists believe that life on Earth may have originated near deep-ocean vents. Balance the following reactions, which are among those taking place near such vents:
a. $\mathrm{CH}_{3} \mathrm{SH}(a q)+\mathrm{CO}(a q) \rightarrow \mathrm{CH}_{3} \mathrm{COSCH}_{3}(a q)+\mathrm{H}_{2} \mathrm{S}(a q)$.
b. $\mathrm{H}_{2} \mathrm{S}(a q)+\mathrm{CO}(a q) \rightarrow \mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H}(a q)+\mathrm{S}_{8}(s)$.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:09

Problem 55

The oxides of nitrogen are biologically reactive substances now known to be formed endogenously in the human lung: $\mathrm{NO}$ is a powerful agent for dilating blood vessels; $\mathrm{N}_{2} \mathrm{O}$ is the anesthetic known as laughing gas; $\mathrm{NO}_{2}$ has an acrid odor and is corrosive to lung tissue. Balance the following reactions for the formation of nitrogen oxides:
a. $\mathrm{N}_{2}(g)+\mathrm{O}_{2}(g) \rightarrow \mathrm{NO}(g)$.
b. $\mathrm{NO}(g)+\mathrm{O}_{2}(g) \rightarrow \mathrm{NO}_{2}(g)$.
c. $\mathrm{NO}(g)+\mathrm{NO}_{3}(g) \rightarrow \mathrm{NO}_{2}(g)$.
d. $\mathrm{N}_{2}(g)+\mathrm{O}_{2}(g) \rightarrow \mathrm{N}_{2} \mathrm{O}(g)$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
04:04

Problem 56

If natural gas contains significant amounts of sulfur as $\mathrm{H}_{2} \mathrm{S}$, it is called sour natural gas. For the gas to be commercially useful as a fuel, the $\mathrm{H}_{2} \mathrm{S}$ must be removed. Once it is separated from the natural gas, it is reacted with oxygen in two different processes to yield either elemental sulfur (S $_{8}$ ), a commercial material that can be sold, or sulfur dioxide $\left(\mathrm{SO}_{2}\right) .$ This sulfur dioxide product can be reacted with more $\mathrm{H}_{2} \mathrm{S}$ to make additional elemental sulfur. Balance the following reactions that describe the production of elemental sulfur.
a. $\mathrm{H}_{2} \mathrm{S}(g)+\mathrm{O}_{2}(g) \rightarrow \mathrm{S}_{8}(s)+\mathrm{H}_{2} \mathrm{O}(g)$.
b. $\mathrm{H}_{2} \mathrm{S}(g)+\mathrm{O}_{2}(g) \rightarrow \mathrm{SO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(g)$.
$^{*} \mathrm{c} . \mathrm{H}_{2} \mathrm{S}(g)+\mathrm{SO}_{2}(g) \rightarrow \mathrm{S}_{8}(s)+\mathrm{H}_{2} \mathrm{O}(\mathrm{g})$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
02:18

Problem 57

Write a balanced chemical equation for each of the following reactions:
a. Dinitrogen pentoxide reacts with sodium metal to produce sodium nitrate and nitrogen dioxide.
b. A mixture of nitric acid and nitrous acid is formed when water reacts with dinitrogen tetroxide.
c. At high pressure, nitrogen monoxide decomposes to dinitrogen monoxide and nitrogen dioxide.
d. Acetylene, $\mathrm{C}_{2} \mathrm{H}_{2},$ burns and becomes carbon dioxide and water vapor.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
02:06

Problem 58

Write a balanced chemical equation for each of the following reactions:
a. Carbon dioxide reacts with carbon to form carbon monoxide.
b. Potassium reacts with water to give potassium hydroxide and hydrogen gas.
c. Phosphorus, $P_{4}$, burns in air to give diphosphorus pentoxide.
d. Octane, $\mathrm{C}_{8} \mathrm{H}_{18},$ burns and becomes carbon dioxide and water vapor.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:37

Problem 59

Does the sum of the masses of the products always equal the sum of the masses of the reactants in a balanced chemical equation?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:37

Problem 60

There are two ways to write the equation for the combustion of ethane:$$\begin{aligned}
\mathrm{C}_{2} \mathrm{H}_{6}(g)+\frac{7}{2} \mathrm{O}_{2}(g) & \rightarrow 3 \mathrm{H}_{2} \mathrm{O}(g)+2 \mathrm{CO}_{2}(g) \\2 \mathrm{C}_{2} \mathrm{H}_{6}(g)+7 \mathrm{O}_{2}(g) & \rightarrow 6 \mathrm{H}_{2} \mathrm{O}(g)+4 \mathrm{CO}_{2}(g)\end{aligned}$$.Do these two different ways of writing the equation affect the calculation of how much $\mathrm{CO}_{2}$ is produced from a known quantity of $\mathrm{C}_{2} \mathrm{H}_{6} ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:24

Problem 61

When $\mathrm{NaHCO}_{3}$ is heated above $270^{\circ} \mathrm{C},$ it decomposes to $\mathrm{Na}_{2} \mathrm{CO}_{3}(s), \mathrm{H}_{2} \mathrm{O}(g),$ and $\mathrm{CO}_{2}(g)$.
a. Write a balanced chemical equation for the decomposition reaction.
b. Calculate the mass of $\mathrm{CO}_{2}$ produced from the decomposition of $25.0 \mathrm{g}$ of $\mathrm{NaHCO}_{3}$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:04

Problem 62

Egyptian Cosmetics $\mathrm{Pb}$ (OH) Cl, one of the lead compounds used in ancient Egyptian cosmetics, was prepared from PbO according to the following recipe:$$\mathrm{PbO}(s)+\mathrm{NaCl}(a q)+\mathrm{H}_{2} \mathrm{O}(\ell) \rightarrow \mathrm{Pb}(\mathrm{OH}) \mathrm{Cl}(s)+\mathrm{NaOH}(a q)$$.How many grams of $\mathrm{PbO}$ and how many grams of $\mathrm{NaCl}$ would be required to produce $10.0 \mathrm{g}$ of $\mathrm{Pb}(\mathrm{OH}) \mathrm{Cl} ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:00

Problem 63

The manufacture of aluminum includes the production of cryolite (Na_AIF_ ) from the following reaction:
$6 \mathrm{HF}(g)+3 \mathrm{NaAlO}_{2}(s) \rightarrow \mathrm{Na}_{3} \mathrm{AlF}_{6}(s)+3 \mathrm{H}_{2} \mathrm{O}(\ell)+\mathrm{Al}_{2} \mathrm{O}_{3}(s)$.
How much NaAlO, (sodium aluminate) is required to produce $1.00 \mathrm{kg}$ of $\mathrm{Na}_{3} \mathrm{AlF}_{6} ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
06:04

Problem 64

Chromium metal can be produced from the high-temperature reaction of $\mathrm{Cr}_{2} \mathrm{O}_{3}$ [chromium(III) oxide] with silicon or aluminum by each of the following reactions:$$\begin{aligned}
\mathrm{Cr}_{2} \mathrm{O}_{3}(s)+2 \mathrm{Al}(\ell) & \rightarrow 2 \mathrm{Cr}(\ell)+\mathrm{Al}_{2} \mathrm{O}_{3}(s) \\2 \mathrm{Cr}_{2} \mathrm{O}_{3}(s)+3 \mathrm{Si}(\ell) & \rightarrow 4 \mathrm{Cr}(\ell)+3 \mathrm{SiO}_{2}(s)\end{aligned}$$.a. Calculate the number of grams of aluminum required to prepare $400.0 \mathrm{g}$ of chromium metal by the first reaction.
b. Calculate the number of grams of silicon required to prepare $400.0 \mathrm{g}$ of chromium metal by the second reaction.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
05:54

Problem 65

Suppose 25 metric tons of coal that is $3.0 \%$ sulfur by mass is burned at an electric power plant ( 1 metric ton $=10^{3} \mathrm{kg}$ ). During combustion, the sulfur is converted into sulfur dioxide. How many tons of sulfur dioxide are produced?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:51

Problem 66

The uranium minerals found in nature must be refined and enriched in $^{235} \mathrm{U}$ before the uranium can be used as a fuel in nuclear reactors. One procedure for enriching uranium relies on the reaction of $\mathrm{UO}_{2}$ with HF to form UF $_{4}$, which is then converted into UF $_{6}$ by reaction with fluorine: $$\begin{array}{c}\mathrm{UO}_{2}(g)+4 \mathrm{HF}(a q) \rightarrow \mathrm{UF}_{4}(g)+2 \mathrm{H}_{2} \mathrm{O}(\ell) \\\mathrm{UF}_{4}(g)+\mathrm{F}_{2}(g) \rightarrow \mathrm{UF}_{6}(g)
\end{array}$$.a. How many kilograms of HF are needed to completely react with $5.00 \mathrm{kg}$ of $\mathrm{UO}_{2} ?$
b. How much UF $_{6}$ can be produced from $850.0 \mathrm{g}$ of $\mathrm{UO}_{2} ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:22

Problem 67

In Brazil automobiles use ethanol, $\mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O},$ as fuel, whereas in the United States we rely on gasoline. Using $\mathrm{C}_{8} \mathrm{H}_{18}$ (octane) to represent gasoline, write balanced chemical equations for the complete combustion of ethanol and octane. Which fuel produces more $\mathrm{CO}_{2}$ per gram of fuel?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
08:11

Problem 68

Driving 1000 miles a month is not unusual for a short-distance commuter. If your vehicle gets 25 mpg, you would use 40 gallons $(\approx 150 \mathrm{L})$ of gasoline every month. If gasoline is approximated as $\mathrm{C}_{8} \mathrm{H}_{18}(d=0.703 \mathrm{g} / \mathrm{mL}),$ how much carbon dioxide does your vehicle emit every month? The unbalanced chemical equation for the reaction is$$ \mathrm{C}_{8} \mathrm{H}_{18}(\ell)+\mathrm{O}_{2}(g) \rightarrow \mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(g)$$.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:23

Problem 69

Chalcopyrite (CuFeS $_{2}$ ) is an abundant copper mineral that can be converted into elemental copper. How much Cu could be produced from $1.00 \mathrm{kg}$ of $\mathrm{CuFeS}_{2} ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
06:18

Problem 70

Mining for Gold Unlike most metals, gold is found in nature as the pure element. Miners in California in 1849 searched for gold nuggets and gold dust in stream beds, where the denser gold could be easily separated from sand and gravel. However, larger deposits of gold are found in veins of rock and can be separated chemically in a two-step process:$$\begin{aligned}&\text { (1) } 4 \mathrm{Au}(s)+8 \mathrm{NaCN}(a q)+\mathrm{O}_{2}(g)+2 \mathrm{H}_{2} \mathrm{O}(\ell) \rightarrow\\&4 \mathrm{NaAu}(\mathrm{CN})_{2}(a q)+4 \mathrm{NaOH}(a q)\end{aligned}$$.$$\begin{aligned}&\text { (2) } 2 \mathrm{NaAu}(\mathrm{CN})_{2}(a q)+\mathrm{Zn}(s) \rightarrow\\&2 \mathrm{Au}(s)+\mathrm{Na}_{2}\left[\mathrm{Zn}(\mathrm{CN})_{4}\right](a q)\end{aligned}$$.If a $1.0 \times 10^{3} \mathrm{kg}$ sample of rock is $0.019 \%$ gold by mass, how much $\mathrm{Zn}$ is needed to react with the gold extracted from the rock? Assume that reactions (1) and (2) are $100 \%$ efficient.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
00:50

Problem 71

What is the difference between an empirical formula and a molecular formula?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:41

Problem 72

Do the empirical and molecular formulas of a compound always have the same percent composition values? Explain your answer.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:55

Problem 73

Is the element with the largest atomic mass always the element present in the highest percentage by mass in a compound? Explain your answer.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
03:10

Problem 74

Sometimes the composition of a compound is expressed as a mole percentage, and sometimes as an atom percentage. Are the values of these parameters likely to be the same for a given compound, or different?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:00

Problem 75

Among the naturally occurring hydrocarbons emitted by plants are three compounds named camphene, carene, and thujene. If all three of these compounds have the same percent composition and the same molar mass, do they have the same empirical formula? Do they have the same molecular formula? Are they isomers?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:51

Problem 76

How might the compounds in Problem 3.75 differ from each other if they have the same molar mass and percent composition?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:44

Problem 77

Gasoline consists primarily of a mixture of the hydrocarbons $\mathrm{C}_{6} \mathrm{H}_{14}, \mathrm{C}_{7} \mathrm{H}_{16}, \mathrm{C}_{8} \mathrm{H}_{18},$ and $\mathrm{C}_{9} \mathrm{H}_{20} .$ What is
the empirical formula of each compound?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
04:16

Problem 78

The biosynthesis of carbohydrate includes the molecules shown below. What is the empirical formula of each compound shown in Figure $\mathrm{P} 3.78 ?$
(FIGURES CANT COPY)

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
02:47

Problem 79

Calculate the percent composition of (a) $\mathrm{Na}_{2} \mathrm{O},$ (b) $\mathrm{NaOH}$
(c) $\mathrm{NaHCO}_{3},$ and $(\mathrm{d}) \mathrm{Na}_{2} \mathrm{CO}_{3}$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
06:22

Problem 80

Calculate the percent composition of (a) sodium sulfate,
(b) dinitrogen tetroxide, (c) strontium nitrate, and
(d) aluminum sulfide.

Bin Chen
Bin Chen
Numerade Educator
01:21

Problem 81

The following compounds have been detected in space. Which of them contains the greatest percentage of carbon by mass? Do any two of the following compounds have the same empirical formula?
a. naphthalene, $\mathrm{C}_{10} \mathrm{H}_{8}$
b. chrysene, $\mathbf{C}_{18} \mathrm{H}_{12}$
c. pentacene, $\mathrm{C}_{22} \mathrm{H}_{14}$
d. pyrene, $\mathrm{C}_{16} \mathrm{H}_{10}$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:57

Problem 82

Of the nitrogen oxides $-\mathrm{N}_{2} \mathrm{O}, \mathrm{NO}, \mathrm{N}_{2} \mathrm{O}_{3}, \mathrm{N}_{2} \mathrm{O}_{2}, \mathrm{NO}_{2},$ and $\mathrm{N}_{2} \mathrm{O}_{4}-$ which are more than $50 \%$ oxygen by mass? Which, if any, have the same empirical formula?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:52

Problem 83

Methane $\left(\mathrm{CH}_{4}\right)$ and tetrafluoromethane $\left(\mathrm{CF}_{4}\right)$ both contain $20 \%$ carbon per mole. Which one has the greater percent $C$ by mass?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:16

Problem 84

Silane $\left(\mathrm{SiH}_{4}\right)$ is used in the electronics industry to manufacture thin films of silicon. What is the percent Si by mass in $\mathrm{SiH}_{4} ?$ Does silane have the same percent Si by mass as disilane, $\mathrm{Si}_{2} \mathrm{H}_{6} ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:12

Problem 85

Surgical-Grade Titanium Medical implants and high-quality jewelry items for body piercings are frequently made of a material known as G23Ti, or surgical-grade titanium. The percent composition of the material is $64.39 \%$ titanium,$24.19 \%$ aluminum, and $11.42 \%$ vanadium. What is the empirical formula for surgical-grade titanium?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
02:31

Problem 86

A sample of an iron-containing compound is $22.0 \%$ iron, $50.2 \%$ oxygen, and $27.8 \%$ chlorine by mass. What is the empirical formula of this compound?

Ronald Prasad
Ronald Prasad
Numerade Educator
03:32

Problem 87

Sour Candy Tartaric acid, $\mathrm{C}_{4} \mathrm{H}_{6} \mathrm{O}_{6},$ and citric acid, $\mathrm{C}_{6} \mathrm{H}_{8} \mathrm{O}_{7},$ are both used commercially to give sour candies (Figure $\mathrm{P} 3.87$ ) their characteristic sour taste. Which compound has the larger percent C by mass?
(IMAGE CAN'T COPY)

Rabia Shuaib
Rabia Shuaib
Numerade Educator
00:38

Problem 88

CFCs (chlorofluorocarbons) are molecules used as refrigerants, but they also contribute to the destruction of the ozone layer. One CFC known as Freon consists of two carbon atoms, two fluorine atoms, and four chlorine atoms. What is the empirical formula of Freon? What is its molecular formula?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
03:15

Problem 89

Asbestosis is a lung disease caused by inhaling asbestos fibers. In addition, fiber from a form of asbestos called chrysotile is considered to be a human carcinogen by the U.S. Department of Health and Human Services. Chrysotile's composition is $26.31 \%$ magnesium, $20.20 \%$ silicon, and $1.45 \%$ hydrogen with the remainder of the mass as oxygen. Determine the empirical formula of chrysotile.

Ronald Prasad
Ronald Prasad
Numerade Educator
00:37

Problem 90

A candle flame produces easily seen specks of soot near the edges of the flame, especially when the candle is moved. A piece of glass held over a candle flame will become coated with soot, which is the result of the incomplete combustion of candle wax. Elemental analysis of a compound extracted from a sample of this soot gave these results: $92.26 \% \mathrm{C}$ and $7.74 \%$ H by mass. Calculate the empirical formula of the compound.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:16

Problem 91

Adenine (135.14 g/mol; 44.44\% $\mathrm{C}, 3.73 \% \mathrm{H}, \text { and } 51.84 \% \mathrm{N})$ was detected in mixtures of HCN, ammonia, and water under conditions that simulate early Earth. This observation suggests a possible origin for one of the bases found in DNA. What are the empirical and molecular formulas for adenine?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:23

Problem 92

Ribose, the sugar found in RNA, has been detected in experiments designed to mimic the conditions of early Earth. If ribose contains $40.00 \% \mathrm{C}$ $6.71 \% \mathrm{H},$ and $53.28 \%$ O, with a molar mass of $150.13 \mathrm{g} / \mathrm{mol}$.What are the empirical and molecular formulas for ribose?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:50

Problem 93

Explain why it is important for combustion analysis to be carried out in an excess of oxygen.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:09

Problem 94

Why is the quantity of $\mathrm{CO}_{2}$ obtained in a combustion analysis not a direct measure of the oxygen content of the starting compound?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:39

Problem 95

Can the results of a combustion analysis ever give the true molecular formula of a compound?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:45

Problem 96

What additional information is needed to determine a molecular formula from the results of an elemental analysis of an organic compound?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:42

Problem 97

If a compound containing nitrogen is subjected to combustion analysis in excess oxygen, what is the most likely molecular formula for the nitrogen-containing product?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
05:25

Problem 98

Suppose an insufficient amount of oxygen is used for a combustion analysis of a hydrocarbon, and some of the carbon is converted to CO rather than to $\mathrm{CO}_{2} .$ Will the empirical formula determined from the results of this analysis be too low or too high in carbon?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
08:20

Problem 99

The combustion of 135.0 mg of a hydrocarbon produces $440.0 \mathrm{mg}$ of $\mathrm{CO}_{2}$ and $135.0 \mathrm{mg}$ of $\mathrm{H}_{2} \mathrm{O} .$ The molar mass of the hydrocarbon is $270 \mathrm{g} / \mathrm{mol}$. Determine the empirical and molecular formulas of this compound.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
02:30

Problem 100

A 0.100 g sample of a compound containing $\mathrm{C}, \mathrm{H},$ and $\mathrm{O}$ is burned in oxygen, producing $0.1783 \mathrm{g}$ of $\mathrm{CO}_{2}$ and $0.0734 \mathrm{g}$ of $\mathrm{H}_{2} \mathrm{O} .$ Determine the empirical formula of the compound.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
10:43

Problem 101

The compound geraniol is on the Food and Drug Administration's GRAS (generally recognized as safe) list and can be used in foods and personal care products. By itself, geraniol smells like roses but it is frequently blended with other fragrances on the GRAS list and then added to products to produce a pleasant peach-or lemon-like aroma. In an analysis, the complete combustion of 175 mg of geraniol produced $499 \mathrm{mg}$ of $\mathrm{CO}_{2}$ and $184 \mathrm{mg}$ of $\mathrm{H}_{2} \mathrm{O} .$ What is the empirical formula for geraniol?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
03:02

Problem 102

The combustion of 40.5 mg of a compound containing $C$, $\mathrm{H},$ and $\mathrm{O},$ and extracted from the bark of the sassafras tree, produces $110.0 \mathrm{mg}$ of $\mathrm{CO}_{2}$ and $22.5 \mathrm{mg}$ of $\mathrm{H}_{2} \mathrm{O} .$ The molar mass of the compound is $162 \mathrm{g} / \mathrm{mol}$. Determine its empirical and molecular formulas.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
11:08

Problem 103

One of the ingredients in the Native American stomachache remedy derived from common chokecherry is caffeic acid. Combustion of $1.00 \times 10^{2} \mathrm{mg}$ of caffeic acid yielded $220 \mathrm{mg}$ of $\mathrm{CO}_{2}$ and $40.3 \mathrm{mg}$ of $\mathrm{H}_{2} \mathrm{O}$ Determine the empirical formula of caffeic acid.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
14:05

Problem 104

Coniine, a substance isolated from poison hemlock, contains only carbon, hydrogen, and nitrogen. Combustion of 5.024 mg of coniine yields $13.90 \mathrm{mg} \mathrm{CO}_{2}$ and $6.048 \mathrm{mg}$ of $\mathrm{H}_{2} \mathrm{O} .$ What is the empirical formula of coniine?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:18

Problem 105

If a reaction vessel contains equal masses of Fe and $\mathrm{S}$, a mass of FeS corresponding to which of the following could theoretically be produced?
a. the sum of the masses of $\mathrm{Fe}$ and $\mathrm{S}$.
b. more than the sum of the masses of Fe and $S$.
c. less than the sum of the masses of Fe and $S$..

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:42

Problem 106

Can the percent yield of a chemical reaction ever exceed $100 \% ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:04

Problem 107

Give two reasons why the actual yield from a chemical reaction is usually less than the theoretical yield.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:51

Problem 108

A chemical reaction produces less than the expected amount of product. Is this result a violation of the law of conservation of mass?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:08

Problem 109

A recipe for 1 cup of hollandaise sauce calls for $\frac{1}{2}$ cup of butter, $\frac{1}{4}$ cup of hot water, 4 egg yolks, and the juice of a medium-sized lemon. How many cups of this sauce can be made from a pound (2 cups) of butter, a dozen eggs, 4 medium lemons, and an unlimited supply of hot water?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
00:52

Problem 110

A factory making toy wagons has 13,466 wheels, 3360 handles, and 2400 wagon beds in stock. What is the maximum number of wagons the factory can make?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
11:18

Problem 111

Given the amounts of reactants shown, calculate the theoretical yield in grams of the product of each of these unbalanced chemical equations.
a. $\mathrm{Cu}_{2} \mathrm{O}(s)+\mathrm{H}_{2}(g) \rightarrow \mathrm{Cu}(s)+\mathrm{H}_{2} \mathrm{O}(\ell)$
$30.0 \mathrm{g} \quad 12.0 \mathrm{g} \quad$ ? $\mathrm{g}$
b. $\mathrm{Mg}(s)+\mathrm{HCl}(g) \rightarrow \mathrm{MgCl}_{2}(s)+\mathrm{H}_{2}(g)$
$24.3 \mathrm{g} \quad 10.0 \mathrm{g}$
$? g$
c. $\mathrm{CuCl}_{2}(a q)+\mathrm{Zn}(s) \rightarrow \mathrm{Cu}(s)+\mathrm{ZnCl}_{2}(a q)$
$1 ? \mathrm{g}$
$11.6 \mathrm{g} \quad 10.0 \mathrm{g}$

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
11:18

Problem 112

Given the amounts of reactants shown, calculate the theoretical yield in grams of the product indicated by the question mark for each of these unbalanced chemical reactions.
a. $\mathrm{Cu}_{2} \mathrm{O}(s)+\mathrm{H}_{2}(g) \rightarrow \mathrm{Cu}(s)+\mathrm{H}_{2} \mathrm{O}(\ell)$
$30.0 \mathrm{g} \quad 12.0 \mathrm{g} \quad$ ? $\mathrm{g}$
b. $\mathrm{Mg}(s)+\mathrm{HCl}(g) \rightarrow \mathrm{MgCl}_{2}(s)+\mathrm{H}_{2}(g)$
$24.3 \mathrm{g} \quad 10.0 \mathrm{g}$
$? \mathrm{g}$
c. $\mathrm{CuCl}_{2}(a q)+\mathrm{Zn}(s) \rightarrow \mathrm{Cu}(s)+\mathrm{ZnCl}_{2}(a q)$
$11.6 \mathrm{g} \quad 10.0 \mathrm{g}$
$? \mathrm{g}$

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
View

Problem 113

Ammonia rapidly reacts with hydrogen chloride, making ammonium chloride. Write a balanced chemical equation for the reaction, and calculate the number of grams of excess reactant when $3.0 \mathrm{g}$ of $\mathrm{NH}_{3}$ reacts with $5.0 \mathrm{g}$ of $\mathrm{HCl}$.

Nicole Basile
Nicole Basile
Numerade Educator
05:06

Problem 114

Sulfur trioxide dissolves in water, producing $\mathrm{H}_{2} \mathrm{SO}_{4} .$ How much sulfuric acid can be produced from $10.0 \mathrm{mL}$ of water $(d=1.00 \mathrm{g} / \mathrm{mL})$ and $25.6 \mathrm{g}$ of $\mathrm{SO}_{3} ?$

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:46

Problem 115

Phosgenite, a lead compound with the formula $\mathrm{Pb}_{2} \mathrm{Cl}_{2} \mathrm{CO}_{3},$ is found in ancient Egyptian cosmetics. Phosgenite was prepared by the reaction of $\mathrm{Pb} \mathrm{O}, \mathrm{NaCl}$ $\mathrm{H}_{2} \mathrm{O},$ and $\mathrm{CO}_{2} .$ An unbalanced equation of the reaction is $\mathrm{PbO}(s)+\mathrm{NaCl}(a q)+\mathrm{H}_{2} \mathrm{O}(\ell)+\mathrm{CO}_{2}(g) \rightarrow$.$$\mathrm{Pb}_{2} \mathrm{Cl}_{2} \mathrm{CO}_{3}(s)+\mathrm{NaOH}(a q)$$,a. Balance the equation.
b. How many grams of phosgenite can be obtained from $10.0 \mathrm{g}$ of $\mathrm{PbO}$ and $10.0 \mathrm{g}$ of $\mathrm{NaCl}$ in the presence of excess water and $\mathrm{CO}_{2} ?$
c. If 2.72 g of phosgenite is produced in the laboratory from the amounts of starting materials stated in part
(b), what is the percent yield of the reaction?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:42

Problem 116

Potassium superoxide, $\mathrm{KO}_{2},$ reacts with carbon dioxide to form potassium carbonate and oxygen:$4 \mathrm{KO}_{2}(s)+2 \mathrm{CO}_{2}(g) \rightarrow 2 \mathrm{K}_{2} \mathrm{CO}_{3}(s)+3 \mathrm{O}_{2}(g)$.This reaction makes potassium superoxide useful in a self-contained breathing apparatus. How much $\mathrm{O}_{2}$ could be produced from $2.50 \mathrm{g}$ of $\mathrm{KO}_{2}$ and $4.50 \mathrm{g}$ of $\mathrm{CO}_{2} ?$

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:21

Problem 117

The reaction of $5.0 \mathrm{g}$ of pentane $\left(\mathrm{C}_{5} \mathrm{H}_{12}\right)$ with $5.0 \mathrm{g}$ of oxygen gas produces $20.4 \mathrm{g}$ of $\mathrm{CO}_{2} .$ What is the percent yield of this reaction?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:27

Problem 118

Baking soda (NaHCO $_{3}$ ) can be made in large quantities by the following reaction:
$\mathrm{NaCl}(a q)+\mathrm{NH}_{3}(a q)+\mathrm{CO}_{2}(a q)+\mathrm{H}_{2} \mathrm{O}(\ell) \rightarrow$.$$\mathrm{NaHCO}_{3}(s)+\mathrm{NH}_{4} \mathrm{Cl}(a q)$$
If $10.0 \mathrm{g}$ of $\mathrm{NaCl}$ reacts with excesses of the other reactants and $4.2 \mathrm{g}$ of $\mathrm{NaHCO}_{3}$ is isolated, what is the percent yield of the reaction?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:50

Problem 119

Yeast converts glucose $\left(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\right)$ into ethanol $(d=0.789 \mathrm{g} / \mathrm{mL})$ in a process
called fermentation. An equation for the reaction can be written as follows:
$$\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}(a q) \rightarrow \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}(\ell)+\mathrm{CO}_{2}(g)$$
a. Write a balanced chemical equation for this fermentation reaction.
b. If $100.0 \mathrm{g}$ of glucose yields $50.0 \mathrm{mL}$ of ethanol, what is the percent yield for the reaction?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
12:08

Problem 120

A 1 -liter sample of seawater contains $19.4 \mathrm{g}$ of $\mathrm{Cl}^{-}, 10.8 \mathrm{g}$ of $\mathrm{Na}^{+},$ and $1.29 \mathrm{g}$ of $\mathrm{Mg}^{2+}$
a. How many moles of each ion are present?
b. If we evaporated the seawater, would there be enough Cl "present to form the chloride salts of all the sodium and magnesium present?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
03:20

Problem 121

As a solution of copper sulfate slowly evaporates, beautiful blue crystals made of copper(II) and sulfate ions form such that water molecules are trapped inside the crystals. The overall formula of the compound is $\mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O}$
a. What is the percent water in this compound?
b. At high temperatures, the water in the compound
is driven off as steam. What mass percentage of the original sample of the blue solid is lost as a result?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
11:16

Problem 122

Aluminum is mined as the mineral bauxite, which consists primarily of $\mathrm{Al}_{2} \mathrm{O}_{3}$ (alumina).
a. How much aluminum is produced from 1 metric ton.
$$\begin{array}{r}\left(1 \text { metric ton }=10^{3} \mathrm{kg}\right) \text { of } \mathrm{Al}_{2} \mathrm{O}_{3} ? \\2 \mathrm{Al}_{2} \mathrm{O}_{3}(s) \rightarrow 4 \mathrm{Al}(s)+3 \mathrm{O}_{2}(g)
\end{array}$$.b. The oxygen produced in part (a) is allowed to react with carbon to produce carbon monoxide:$$\mathrm{O}_{2}(g)+2 \mathrm{C}(s) \rightarrow 2 \mathrm{CO}(g)$$.Balance the following equation describing the reaction of alumina with carbon:$$\mathrm{Al}_{2} \mathrm{O}_{3}(s)+\mathrm{C}(s) \rightarrow \mathrm{Al}(s)+\mathrm{CO}(g)$$.
c. How much CO can be produced from the $\mathrm{O}_{2}$ made in part (a)?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
14:46

Problem 123

Chemistry of Copper Production "Native," or elemental, copper can be found in nature, but most copper is mined as oxide or sulfide minerals. Chalcopyrite (CuFeS $_{2}$ ) is one copper mineral that can be converted to elemental copper in a series of chemical steps. Reacting chalcopyrite with oxygen at high temperature produces a mixture of copper sulfide and iron oxide. The iron oxide is separated from CuS by reaction with sand. CuS is converted to $\mathrm{Cu}_{2} \mathrm{S},$ and the $\mathrm{Cu}_{2} \mathrm{S}$ is then burned in air to produce $\mathrm{Cu}$ and $\mathrm{SO}_{2}$ :(1) $2 \operatorname{CuFeS}_{2}(s)+3 \mathrm{O}_{2}(g) \rightarrow$
$2 \mathrm{CuS}(s)+2 \mathrm{FeO}(s)+2 \mathrm{SO}_{2}(g)$
(2) $\mathrm{FeO}(s)+\mathrm{SiO}_{2}(s) \rightarrow \mathrm{FeSiO}_{3}(s)$
(3) $2 \mathrm{CuS}(s) \rightarrow \mathrm{Cu}_{2} \mathrm{S}(s)+\frac{1}{8} \mathrm{S}_{8}(s)$
(4) $\mathrm{Cu}_{2} \mathrm{S}(s)+\mathrm{O}_{2}(g) \rightarrow 2 \mathrm{Cu}(s)+\mathrm{SO}_{2}(g)$
An average copper penny minted in the 1960 s has a mass of about $3.0 \mathrm{g}$
a. How much chalcopyrite had to be mined to produce one dollar's worth of pennies?
b. How much chalcopyrite had to be mined to produce one dollar's worth of pennies if reaction 1 above had
a percent yield of $85 \%$ and reactions $2,3,$ and 4 had percent yields of essentially $100 \%$
c. How much chalcopyrite had to be mined to produce one dollar's worth of pennies if each reaction involving copper proceeded with an $85 \%$ yield?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
02:19

Problem 124

Gold can be extracted from the surrounding rock by using a solution of sodium cyanide. While effective for isolating gold, toxic cyanide finds its way into watersheds, causing environmental damage and harming human health.$4 \mathrm{Au}(s)+8 \mathrm{NaCN}(a q)+\mathrm{O}_{2}(g)+2 \mathrm{H}_{2} \mathrm{O}(\ell) \rightarrow$.$4 \mathrm{NaAu}(\mathrm{CN})_{2}(a q)+4 \mathrm{NaOH}(a q)$
$2 \mathrm{NaAu}(\mathrm{CN})_{2}(a q)+\mathrm{Zn}(s) \rightarrow 2 \mathrm{Au}(s)+\mathrm{Na}_{2}\left[\mathrm{Zn}(\mathrm{CN})_{4}\right](a q)$.a. If a sample of rock contains $0.009 \%$ gold by mass, how much $\mathrm{NaCN}$ is needed to extract the gold from 1 metric ton ( 1 metric ton $=10^{3} \mathrm{kg}$ ) of rock as $\mathrm{NaAu}(\mathrm{CN})_{2} ?$
b. How much zinc is needed to convert the $\mathrm{NaAu}(\mathrm{CN})_{2}$ from part (a) to metallic gold?
c. The gold recovered in part (b) is manufactured into a gold ingot in the shape of a cube. The density of gold is $19.3 \mathrm{g} / \mathrm{cm}^{3} .$ How big is the cube of gold?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
28:03

Problem 125

Uranium oxides used in the preparation of fuel for nuclear reactors are separated from other metals in minerals by converting the uranium to $\mathrm{UO}_{x}\left(\mathrm{NO}_{3}\right)_{y}\left(\mathrm{H}_{2} \mathrm{O}\right)_{z},$ where uranium has a positive charge ranging from $3+$ to $6+$
a. Roasting UO $_{x}\left(\mathrm{NO}_{3}\right)_{y}\left(\mathrm{H}_{2} \mathrm{O}\right)_{z}$ at $400^{\circ} \mathrm{C}$ leads to loss of itrogen oxides, leaving behind a product with the formula $\mathrm{U}_{a} \mathrm{O}_{b}$ that is $83.22 \% \mathrm{U}$ by mass. What are the values of $a$ and $b ?$ What is the charge on $\mathrm{U}$ in $\mathrm{U}_{a} \mathrm{O}_{b} ?$b. Higher temperatures produce a different uranium oxide, $\mathrm{U}_{c} \mathrm{O}_{d},$ with a higher uranium content, $84.8 \% \mathrm{U} .$ What are the values of $c$ and $d ?$ What is the charge on $\mathrm{U}$ in $\mathrm{U}_{a} \mathrm{O}_{b} ?$
c. The values of $x, y,$ and $z$ in $\mathrm{UO}_{x}\left(\mathrm{NO}_{3}\right)_{y}\left(\mathrm{H}_{2} \mathrm{O}\right)_{z}$ are found by gently heating the compound to remove all of the water. In a laboratory experiment, $1.328 \mathrm{g}$ of $\mathrm{UO}_{x}\left(\mathrm{NO}_{3}\right)_{y}\left(\mathrm{H}_{2} \mathrm{O}\right)_{z}$ produced $1.042 \mathrm{g}$ of $\mathrm{UO}_{x}\left(\mathrm{NO}_{3}\right)_{y}$
Continued heating generated $0.742 \mathrm{g}$ of $\mathrm{U}_{n} \mathrm{O}_{m} .$ Using the information in parts (a) and (b), calculate $x, y,$ and $z$.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
13:17

Problem 126

Large quantities of fertilizer are washed into the Mississippi River from agricultural land in the Midwest. The excess nutrients collect in the Gulf of Mexico, promoting the growth of algae and endangering other aquatic life.a. One commonly used fertilizer is ammonium nitrate. What is the chemical formula of ammonium nitrate?
b. Corn farmers typically use $5.0 \times 10^{3} \mathrm{kg}$ of ammonium nitrate per square kilometer of cornfield per year. Ammonium nitrate can be prepared by the following reaction:
$$\mathrm{NH}_{3}(a q)+\mathrm{HNO}_{3}(a q) \rightarrow \mathrm{NH}_{4} \mathrm{NO}_{3}(a q)$$
How much nitric acid would be required to make the fertilizer needed for $1 \mathrm{km}^{2}$ of cornfield per year?
c. The ammonium ions can be converted into $\mathrm{NO}_{3}^{-}$ by bacterial action.
$\mathrm{NH}_{4}^{+}(a q)+2 \mathrm{O}_{2}(g) \rightarrow \mathrm{NO}_{3}^{-}(a q)+\mathrm{H}_{2} \mathrm{O}(\ell)+2 \mathrm{H}^{+}(a q)$
If $10 \%$ of the ammonium component of $5.0 \times 10^{2} \mathrm{kg}$ of fertilizer ends up as nitrate, how much oxygen would be consumed?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
06:19

Problem 127

Composition of Over-the-Counter Medicines Calculate the number of molecules or formula units of compound in each of the following common, over-the-counter medications:
a. ibuprofen, a pain reliever and fever reducer that contains $200.0 \mathrm{mg}$ of the active ingredient, $\mathrm{C}_{13} \mathrm{H}_{18} \mathrm{O}_{2}$
b. an antacid containing 500.0 mg of calcium carbonate
c. an allergy tablet containing 4 mg of chlorpheniramine
$$\left(\mathrm{C}_{16} \mathrm{H}_{19} \mathrm{ClN}_{2}\right)$$.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
13:13

Problem 128

The common pain relievers aspirin $\left(\mathrm{C}_{9} \mathrm{H}_{8} \mathrm{O}_{4}\right),$ acetaminophen $\left(\mathrm{C}_{8} \mathrm{H}_{9} \mathrm{NO}_{2}\right),$ and
naproxen sodium $\left(\mathrm{C}_{14} \mathrm{H}_{13} \mathrm{O}_{3} \mathrm{Na}\right)$ are all available in tablets containing $200.0 \mathrm{mg}$ of the active ingredient. Which compound contains the greatest number of molecules per tablet? How many molecules of the active ingredient are present in each tablet?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
07:05

Problem 129

Some catalytic converters in automobiles contain the manganese oxides $\mathrm{Mn}_{2} \mathrm{O}_{3}$ and $\mathrm{MnO}_{2}$a. Give the names of $\mathrm{Mn}_{2} \mathrm{O}_{3}$ and $\mathrm{MnO}_{2}$.
b. Calculate the percent manganese by mass in $\mathrm{Mn}_{2} \mathrm{O}_{3}$ and $\mathrm{MnO}_{2}$.c. Explain how $\mathrm{Mn}_{2} \mathrm{O}_{3}$ and $\mathrm{MnO}_{2}$ are consistent with the law of multiple proportions.

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
10:27

Problem 130

Several chemical reactions have been proposed for the formation of organic compounds from inorganic precursors. Here is one of them:$\mathrm{H}_{2} \mathrm{S}(g)+\mathrm{FeS}(s)+\mathrm{CO}_{2}(g) \rightarrow \mathrm{FeS}_{2}(s)+\mathrm{HCO}_{2} \mathrm{H}(\ell)$
a. Identify the ions in $\mathrm{FeS}$ and $\mathrm{FeS}_{2} .$ Give correct names for each compound.
"b. How much HCO $_{2} \mathrm{H}$ is obtained by reacting $1.00 \mathrm{g}$ of FeS, $0.50 \mathrm{g}$ of $\mathrm{H}_{2} \mathrm{S},$ and $0.50 \mathrm{g}$ of $\mathrm{CO}_{2}$ if the reaction results in a $50.0 \%$ yield?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
07:04

Problem 131

The formation of organic compounds by the reaction of iron(II) sulfide with carbonic acid is described by the following chemical equation:$$2 \mathrm{FeS}+\mathrm{H}_{2} \mathrm{CO}_{3} \rightarrow 2 \mathrm{FeO}+1 / n\left(\mathrm{CH}_{2} \mathrm{O}\right)_{n}+2 \mathrm{S}$$
a. How much FeO is produced starting with $1.50 \mathrm{g}$ of FeS and 0.525 mol of $\mathrm{H}_{2} \mathrm{CO}_{3}$ if the reaction results in a $78.5 \%$ yield?
"b. If the carbon-containing product has a molar mass of $3.00 \times 10^{2} \mathrm{g} / \mathrm{mol},$ what is the chemical formula of the product?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:53

Problem 132

On the seafloor, iron(II) oxide reacts with water to form $\mathrm{Fe}_{3} \mathrm{O}_{4}$ and hydrogen in a process called serpentization.
a. Balance the following equation for serpentization:
$\mathrm{FeO}(s)+\mathrm{H}_{2} \mathrm{O}(\ell) \rightarrow \mathrm{Fe}_{3} \mathrm{O}_{4}(s)+\mathrm{H}_{2}(g)$.
b. When $\mathrm{CO}_{2}$ is present, the product is methane, not hydrogen. Balance the following chemical equation:
$\mathrm{FeO}(s)+\mathrm{H}_{2} \mathrm{O}(\ell)+\mathrm{CO}_{2}(g) \rightarrow \mathrm{Fe}_{3} \mathrm{O}_{4}(s)+\mathrm{CH}_{4}(g)$.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:13

Problem 133

The solar wind is made up of ions, mostly protons, flowing out from the sun at about $400 \mathrm{km} / \mathrm{s} .$ Near Earth, each cubic kilometer of interplanetary space contains, on average, $6 \times 10^{15}$ solar-wind ions. How many moles of ions are in a cubic kilometer of near-Earth space?

David Collins
David Collins
Numerade Educator
02:20

Problem 134

The famous Hope Diamond at the Smithsonian National Museum of Natural History has a mass of 45.52 carats (Figure $\mathrm{P} 3.134$ ). Diamond is a crystalline form of carbon.
a. How many moles of carbon are in the Hope Diamond (1 carat $=200.0 \mathrm{mg}$ )?
b. How many carbon atoms are in the diamond?
(FIGURE CANT COPY)

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
02:51

Problem 135

E-85 is an alternative fuel for automobiles and light trucks that consists of $85 \%$ (by volume) ethanol, $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}$ and $15 \%$ gasoline. The density of ethanol is $0.79 \mathrm{g} / \mathrm{mL}$ How many moles of ethanol are in a gallon of $\mathrm{E}-85 ?$

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
03:53

Problem 136

A $100.00 \mathrm{g}$ sample of white powder $\mathrm{A}$ is heated to $550^{\circ} \mathrm{C}$ At that temperature the powder decomposes, giving off colorless gas $\mathrm{B}$, which is denser than air and is neither flammable nor does it support combustion. The products also include $56 \mathrm{g}$ of a second white powder $\mathrm{C}$. When gas B is bubbled through a solution of calcium hydroxide, substance A reforms. What are the identities of substances $A, B,$ and $C ?$

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
03:35

Problem 137

You are given a $0.6240 \mathrm{g}$ sample of a substance with the generic formula MCl $_{2}\left(\mathrm{H}_{2} \mathrm{O}\right)_{2} .$ After complete drying of the sample (which means removing the 2 mol of $\mathrm{H}_{2} \mathrm{O}$ per mole of $\mathrm{MCl}_{2}$ ), the sample has a mass of $0.5471 \mathrm{g} .$ What is the identity of element M?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:19

Problem 138

A compound found in crude oil consists of $93.71 \%$ C and $6.29 \%$ H by mass. The molar mass of the compound is $128 \mathrm{g} / \mathrm{mol} .$ What is its molecular formula?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
01:26

Problem 139

A reaction vessel for synthesizing ammonia by reacting nitrogen and hydrogen is charged with $6.04 \mathrm{kg}$ of $\mathrm{H}_{2}$ and excess $\mathrm{N}_{2} .$ A total of $28.0 \mathrm{kg}$ of $\mathrm{NH}_{3}$ is produced. What is the percent yield of the reaction?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
02:38

Problem 140

If a cube of table sugar, which is made of sucrose, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11},$ is added to concentrated sulfuric acid, the acid "dehydrates" the sugar, removing the hydrogen and oxygen from it and leaving behind a lump of carbon. What percentage of the initial mass of sugar is carbon?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:46

Problem 141

A power plant burns $1.0 \times 10^{2}$ metric tons of coal that contains $3.0 \%$ (by mass) sulfur ( 1 metric ton $=10^{3} \mathrm{kg}$ ). The sulfur is converted to $\mathrm{SO}_{2}$ during combustion.
a. How many metric tons of $\mathrm{SO}_{2}$ are produced?
b. When $\mathrm{SO}_{2}$ escapes into the atmosphere it may combine with $\mathrm{O}_{2}$ and $\mathrm{H}_{2} \mathrm{O},$ forming sulfuric acid, $\mathrm{H}_{2} \mathrm{SO}_{4} .$ Write a balanced chemical equation describing this reaction.
c. How many metric tons of sulfuric acid, a component of acid rain, could be produced from the quantity of $\mathrm{SO}_{2}$ calculated in part (a)?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
03:59

Problem 142

With respect to the previous question, one way to reduce the formation of acid rain involves trapping the $\mathrm{SO}_{2}$ by passing smokestack gases through a spray of calcium oxide and $\mathrm{O}_{2} .$ The product of this reaction is calcium sulfate.
a. Write a balanced chemical equation describing this reaction.
b. How many metric tons of calcium sulfate would be produced from each ton of $\mathrm{SO}_{2}$ that is trapped?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
03:17

Problem 143

In the early 20 th century, Londoners suffered from severe air pollution caused by burning high-sulfur coal. The sulfur dioxide that was emitted into the air mixed with London fog, forming sulfuric acid. For every gram of sulfur that was burned, how many grams of sulfuric acid could have formed?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
03:25

Problem 144

The burner in a gas grill mixes 24 volumes of air for every one volume of propane $\left(\mathrm{C}_{3} \mathrm{H}_{8}\right)$ fuel. Like all gases, the volume that propane occupies is directly proportional to the number of moles of it at a given temperature and pressure. Air is $21 \%$ (by volume) $\mathrm{O}_{2} .$ Is the flame produced by the burner fuel-rich (excess propane in the reaction mixture), fuel-lean (not enough propane), or stoichiometric (just right)?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
01:17

Problem 145

A common mineral in Earth's crust has the chemical composition $34.55 \%$ Mg, $19.96 \%$ Si, and $45.49 \%$ O. What is its empirical formula?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
02:00

Problem 146

Some indoor air-purification systems work by converting a little of the oxygen in the air to ozone, which oxidizes mold and mildew spores and other biological air pollutants. The chemical equation for the ozone generation reaction is,$$3 \mathrm{O}_{2}(g) \rightarrow 2 \mathrm{O}_{3}(g)$$.It is claimed that one such system generates $4.0 \mathrm{g}$ of $\mathrm{O}_{3}$ per hour from dry air passing through the purifier at a flow of $5.0 \mathrm{L} / \mathrm{min.}$ If 1 liter of indoor air contains $0.28 \mathrm{g}$ of $\mathrm{O}_{2}$.
a. what fraction of the molecules of $\mathrm{O}_{2}$ is converted to $\mathrm{O}_{3}$ by the air purifier?
b. what is the percent yield of the ozone generation reaction?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
03:03

Problem 147

Rebreathing Devices In the first episode of George Lucas's Star Wars series, Qui-Gon Jinn and Obi-Wan Kenobi
can visit the underwater world of the Gungans only by using A99 Aquata Breathers, which allow them to survive underwater for up to two hours. While the tiny devices may be from the farfetched world of science fiction, current technology exists for transforming carbon dioxide to oxygen. These self-contained rebreathers are used by a select group of underwater cave explorers and can act as self-rescue devices. The chemistry is based on the following chemical reactions, using either potassium superoxide or sodium peroxide:$$\begin{array}{l}4 \mathrm{KO}_{2}(s)+2 \mathrm{CO}_{2}(g) \rightarrow 2 \mathrm{K}_{2}\mathrm{CO}_{3}(s)+3 \mathrm{O}_{2}(g) \\2 \mathrm{Na}_{2} \mathrm{O}_{2}(s)+2 \mathrm{CO}_{2}(g) \rightarrow 2 \mathrm{Na}_{2} \mathrm{CO}_{3}(s)+\mathrm{O}_{2}(g)\end{array}$$.a. The respiratory rate at rest for an average, healthy adult is 12 breaths per minute. If the average breath takes in $0.500 \mathrm{L}$ of $\mathrm{O}_{2}(d=1.429 \mathrm{g} / \mathrm{L})$ into the lungs, how many
grams of $\mathrm{KO}_{2}$ are needed to produce enough oxygen for two hours underwater?
b. Would you need more or less $\mathrm{Na}_{2} \mathrm{O}_{2}$ to produce an equivalent amount of oxygen?
c. Given the densities of $\mathrm{KO}_{2}(2.14 \mathrm{g} / \mathrm{mL})$ and $\mathrm{Na}_{2} \mathrm{O}_{2}$
$(2.805 \mathrm{g} / \mathrm{mL}),$ which solid material would occupy less volume in a rebreather device?

Kim Trang Nguyen
Kim Trang Nguyen
Numerade Educator
View

Problem 148

Socks containing silver nanoparticles embedded in the fabric are currently marketed as an antidote to smelly socks. Silver is known to have antimicrobial properties, and silver ions are toxic to aquatic life. A study at Arizona State University found that much of the silver particles are lost upon laundering the socks in mild acid.a. Each sock in the study began with $1360 \mu \mathrm{g}$ of silver. How many moles of silver are contained in each sock?b. As much as $650 \mu \mathrm{g}$ of silver was lost after four washings. What percent of the silver was lost?

Susan Hallstrom
Susan Hallstrom
Numerade Educator