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Chemical Principles

Steven S. Zumdahl, Donald J. DeCoste

Chapter 2

Atoms, Molecules, and Ions - all with Video Answers

Educators

Chapter Questions

05:14

Problem 1

You may have noticed that when water boils, you can see bubbles that rise to the surface of the water. What is inside these bubbles? Explain.
a. air
d. water vapor
b. hydrogen and oxygen gas
e. carbon dioxide gas
c. oxygen gas

Ronald Prasad
Ronald Prasad
Numerade Educator
02:35

Problem 2

Which of the following is true about an individual atom?
a. An individual atom should be considered a solid.
b. An individual atom should be considered a liquid.
c. An individual atom should be considered a gas.
d. The state of the atom depends on which element it is.
e. An individual atom cannot be considered a solid, liquid, or gas.
Justify your choice, and for those you did not choose, explain why they are incorrect.

Lottie Adams
Lottie Adams
Numerade Educator
02:49

Problem 3

How would you go about finding the number of "chalk molecules" it takes to write your name on the board? Explain what you would need to do and provide a sample calculation.

Lottie Adams
Lottie Adams
Numerade Educator
04:11

Problem 4

These questions concern the work of J. J. Thomson:
a. From what you know of Thomson's work, which particles do you think he would believe are most important in the formation of compounds (chemical changes) and why?
b. Of the remaining two subatomic particles, which do you place second in importance for forming compounds and why?
c. Propose three models that explain Thomson's findings and evaluate them. Include Thomson's findings.

Crystal Wang
Crystal Wang
Numerade Educator
03:53

Problem 5

Heat is applied to an ice cube in a closed container until only steam is present. Draw a representation of this process, assuming you can see it at an extremely high level of magnification. What happens to the size of the molecules? What happens to the total mass of the sample?

LJ
Lena Jake
Numerade Educator
02:34

Problem 6

You have a chemical in a sealed glass container filled with air. The setup is sitting on a balance, as shown. The chemical is ignited by means of a magnifying glass focusing sunlight on the reactant. After the chemical has completely burned, which of the following is true? Explain your answer.
a. The balance will read less than 250.0 g .
b. The balance will read 250.0 g .
c. The balance will read greater than 250.0 g .
d. Cannot be determined without knowing the identity of the chemical.

Jennifer Hudspeth
Jennifer Hudspeth
Numerade Educator
01:06

Problem 7

The vitamin niacin (nicotinic acid, $\mathrm{C}_6 \mathrm{H}_5 \mathrm{NO}_2$ ) can be isolated from a variety of natural sources such as liver, yeast, milk, and whole grain. It also can be synthesized from commercially available materials. From a nutritional point of view, which source of nicotinic acid is best for use in a multivitamin tablet? Why?

LJ
Lena Jake
Numerade Educator
00:14

Problem 8

One of the best indications of a useful theory is that it raises more questions for further experimentation than it originally answered. Is this true of Dalton's atomic theory? Give examples.

Christopher Dzorkpata
Christopher Dzorkpata
Numerade Educator
01:28

Problem 9

Dalton assumed that all atoms of the same element are identical in all their properties. Explain why this assumption is not valid.

David Collins
David Collins
Numerade Educator
03:31

Problem 10

How does Dalton's atomic theory account for each of the following?
a. the law of conservation of mass
b. the law of definite proportion
c. the law of multiple proportions

Kendrick Buford
Kendrick Buford
Numerade Educator
04:08

Problem 11

What refinements had to be made in Dalton's atomic theory to account for Gay-Lussac's results on the combining volumes of gases?

Rabia Shuaib
Rabia Shuaib
Numerade Educator
01:49

Problem 12

Which (if any) of the following can be determined by knowing the number of protons in a neutral element? Explain your answer.
a. the number of neutrons in the neutral element
b. the number of electrons in the neutral element
c. the name of the element

LJ
Lena Jake
Numerade Educator
01:03

Problem 13

The average mass of a carbon atom is 12.011 . Assuming you were able to pick up only one carbon atom, the chance that you would randomly get one with a mass of 12.011 is
a. $0 \%$.
d. $12.011 \%$.
b. $0.011 \%$.
e. greater than $50 \%$.
c. about $12 \%$.
f. None of these is true.
Explain.

Lottie Adams
Lottie Adams
Numerade Educator
01:19

Problem 14

Which of the following explain how an ion is formed? Explain your answer.
a. adding or subtracting protons to/from an atom
b. adding or subtracting neutrons to/from an atom
c. adding or subtracting electrons to/from an atom

Mehrnaz Siavoshi
Mehrnaz Siavoshi
Numerade Educator
01:29

Problem 15

The formula of water is $\mathrm{H}_2 \mathrm{O}$. Which of the following is indicated by this formula? Explain your answer.
a. the mass of hydrogen is twice that of oxygen in each molecule
b. there are two hydrogen atoms and one oxygen atom per water molecule
c. the mass of oxygen is twice that of hydrogen in each molecule
d. there are two oxygen atoms and one hydrogen atom per water molecule

Lottie Adams
Lottie Adams
Numerade Educator
03:29

Problem 16

Why do we call $\mathrm{Ba}\left(\mathrm{NO}_3\right)_2$ barium nitrate, but we call $\mathrm{Fe}\left(\mathrm{NO}_3\right)_2$ iron(II) nitrate?

Kendrick Buford
Kendrick Buford
Numerade Educator
02:23

Problem 17

Why is calcium dichloride not the correct systematic name for $\mathrm{CaCl}_2$ ?

LJ
Lena Jake
Numerade Educator
01:41

Problem 18

Explain the law of conservation of mass, the law of definite proportion, and the law of multiple proportions.

Ly Tran
Ly Tran
Numerade Educator
04:40

Problem 19

A reaction of 1 L of chlorine gas $\left(\mathrm{Cl}_2\right)$ with 5 L of fluorine gas ( $\mathrm{F}_2$ ) yields 2 L of a gaseous product. All gas volumes are at the same temperature and pressure. What is the formula of the gaseous product?

Kendrick Buford
Kendrick Buford
Numerade Educator
01:27

Problem 20

When mixtures of gaseous $\mathrm{H}_2$ and gaseous $\mathrm{Cl}_2$ react, a product forms that has the same properties regardless of the relative amounts of $\mathrm{H}_2$ and $\mathrm{Cl}_2$ used.
a. How is this result interpreted in terms of the law of definite proportion?
b. When a volume of $\mathrm{H}_2$ reacts with an equal volume of $\mathrm{Cl}_2$ at the same temperature and pressure, what volume of product having the formula HCl is formed?

Ly Tran
Ly Tran
Numerade Educator
02:10

Problem 21

Observations of the reaction between nitrogen gas and hydrogen gas show us that 1 volume of nitrogen reacts with 3 volumes of hydrogen to make 2 volumes of gaseous product, as shown below:
Determine the formula of the product and justify your answer.

Ricardo Moreno
Ricardo Moreno
Numerade Educator
04:36

Problem 22

The three most stable oxides of carbon are carbon monoxide ( CO$)$, carbon dioxide $\left(\mathrm{CO}_2\right)$, and carbon suboxide $\left(\mathrm{C}_3 \mathrm{O}_2\right)$. The molecules can be represented as
Explain how these molecules illustrate the law of multiple proportions.

Kendrick Buford
Kendrick Buford
Numerade Educator
02:52

Problem 23

Hydrazine, ammonia, and hydrogen azide all contain only nitrogen and hydrogen. The mass of hydrogen that combines with 1.00 g of nitrogen for each compound is $1.44 \times 10^{-1} \mathrm{~g}, 2.16 \times 10^{-1} \mathrm{~g}$, and $2.40 \times 10^{-2} \mathrm{~g}$, respectively. Show how these data illustrate the law of multiple proportions.

Kendrick Buford
Kendrick Buford
Numerade Educator
01:44

Problem 24

Consider 80.0 g samples of two different compounds consisting of only carbon and oxygen. One of the compounds consists of 21.8 g of carbon, and the other has 34.3 g of carbon. Determine the ratio in whole numbers of the masses of carbon that combine with 1.00 g of oxygen between the two compounds.

Ly Tran
Ly Tran
Numerade Educator
04:58

Problem 25

Early tables of atomic weights (masses) were generated by measuring the mass of a substance that reacts with 1.00 g of oxygen. Given the following data and taking the atomic mass of hydrogen as 1.00 , generate a table of relative atomic masses for oxygen, sodium, and magnesium.
$$
\begin{array}{lcc}
\text { Element } & \begin{array}{c}
\text { Mass That Combines } \\
\text { with } 1.00 \mathrm{~g} \text { Oxygen }
\end{array} & \begin{array}{c}
\text { Assumed } \\
\text { Formula }
\end{array} \\
\hline \text { Hydrogen } & 0.126 \mathrm{~g} & \mathrm{HO} \\
\text { Sodium } & 2.875 \mathrm{~g} & \mathrm{NaO} \\
\text { Magnesium } & 1.500 \mathrm{~g} & \mathrm{MgO}
\end{array}
$$
How do your values compare with those in the periodic table? How do you account for any differences?

Kendrick Buford
Kendrick Buford
Numerade Educator
01:55

Problem 26

What evidence led to the conclusion that cathode rays had a negative charge? Is there a difference between a cathode ray and a $\beta$ particle?

Kendrick Buford
Kendrick Buford
Numerade Educator
02:32

Problem 27

From the information in this chapter on the mass of the proton, the mass of the electron, and the sizes of the nucleus and the atom, calculate the densities of a hydrogen nucleus and a hydrogen atom.

Ly Tran
Ly Tran
Numerade Educator
02:45

Problem 29

A chemist in a galaxy far, far away performed the Millikan oil drop experiment and got the following results for the charge on various drops. What is the charge of the electron in zirkombs?
$2.56 \times 10^{-12}$ zirkombs
$7.68 \times 10^{-12}$ zirkombs
$3.84 \times 10^{-12}$ zirkombs
$6.40 \times 10^{-13}$ zirkombs

Kendrick Buford
Kendrick Buford
Numerade Educator
00:56

Problem 30

Do the proton and the neutron have exactly the same mass? How do the masses of the proton and the neutron compare with the mass of the electron? Which particles make the greatest contribution to the mass of an atom? Which particles make the greatest contribution to the chemical properties of an atom?

Natalie Britton
Natalie Britton
Numerade Educator
02:22

Problem 31

Consider Ernest Rutherford's $\alpha$-particle bombardment experiment illustrated in Fig. 2.11. How did the results of this experiment lead Rutherford away from the plum pudding model of the atom to propose the nuclear model of the atom?

Kendrick Buford
Kendrick Buford
Numerade Educator
08:17

Problem 32

Distinguish between the following terms.
a. molecule versus ion
b. covalent bonding versus ionic bonding
c. molecule versus compound
d. anion versus cation

Ronald Prasad
Ronald Prasad
Numerade Educator
00:56

Problem 33

What is the distinction between atomic number and mass number? Between mass number and atomic mass?

Ronald Prasad
Ronald Prasad
Numerade Educator
02:45

Problem 34

a. Classify the following elements as metals or nonmetals.
$$
\begin{array}{lll}
\mathrm{Mg} & \mathrm{Si} & \mathrm{Rn} \\
\mathrm{Ti}_{\mathrm{Au}} & \mathrm{Ge} & \mathrm{Eu} \\
\mathrm{Au} & \mathrm{B} & \mathrm{Am} \\
\mathrm{Bi} & \mathrm{At} & \mathrm{Br}
\end{array}
$$
b. The distinction between metals and nonmetals is really not a clear one. Some elements, called metalloids, are intermediate in their properties. Which of these elements would you reclassify as metalloids? What other elements in the periodic table would you expect to be metalloids?

Ly Tran
Ly Tran
Numerade Educator
02:12

Problem 35

a. List the noble gas elements. Which of the noble gases has only radioactive isotopes? (This situation is indicated on most periodic tables by parentheses around the mass of the element. See inside front cover.)
b. Which lanthanide element and which transition element have only radioactive isotopes?

Kendrick Buford
Kendrick Buford
Numerade Educator
02:36

Problem 36

Consider the elements of the carbon family: $\mathrm{C}, \mathrm{Si}, \mathrm{Ge}, \mathrm{Sn}$, and Pb . What is the trend in metallic character as one goes down a group in the periodic table? What is the trend in metallic character going from left to right across a period in the periodic table?

Kendrick Buford
Kendrick Buford
Numerade Educator
02:29

Problem 37

Identify the elements that correspond to the following atomic numbers. Label each as either a noble gas, a halogen, an alkali metal, an alkaline earth metal, a transition metal, a lanthanide metal, or an actinide metal.
a. 17
e. 2
b. 4
f. 92
c. 63
g. 55
d. 72

Kendrick Buford
Kendrick Buford
Numerade Educator
02:42

Problem 38

A chemistry instructor makes the following claim: "Consider that if the nucleus were the size of a grape, the electrons would be about 1 mile away on average." Is this claim reasonably accurate? Provide mathematical support.

LJ
Lena Jake
Numerade Educator
00:48

Problem 38

The number of protons in an atom determines the identity of the atom. What does the number and arrangement of the electrons in an atom determine? What does the number of neutrons in an atom determine?

Ly Tran
Ly Tran
Numerade Educator
00:43

Problem 39

For lighter, stable isotopes, the ratio of the mass number to the atomic number is close to a certain value. What is the value? What happens to the value of the mass number to atomic number ratio as stable isotopes become heavier?

Ly Tran
Ly Tran
Numerade Educator
01:13

Problem 40

For each of the following sets of elements, label each as either noble gases, halogens, alkali metals, alkaline earth metals, or transition metals.
a. $\mathrm{Ti}, \mathrm{Fe}, \mathrm{Ag}$
d. $\mathrm{Ne}, \mathrm{Kr}, \mathrm{Xe}$
b. $\mathrm{Mg}, \mathrm{Sr}, \mathrm{Ba}$
e. $\mathrm{F}, \mathrm{Br}, \mathrm{I}$
c. $\mathrm{Li}, \mathrm{K}, \mathrm{Rb}$

David Collins
David Collins
Numerade Educator
01:42

Problem 41

What number of protons and neutrons are contained in the nucleus of each of the following atoms? Assuming each atom is uncharged, what number of electrons are present?
a. ${ }_{92}^{235} \mathrm{U}$
d. ${ }_{82}^{208} \mathrm{~Pb}$
b. ${ }_{13}^{27} \mathrm{Al}$
e. ${ }_{37}^{\frac{8}{3}} \mathrm{Rb}$
c. ${ }_{26}^{57} \mathrm{Fe}$
f. ${ }_{20}^{41} \mathrm{Ca}$

Anand Jangid
Anand Jangid
Numerade Educator
06:02

Problem 42

Write the atomic symbol ( $\left.\frac{1}{2} \mathrm{X}\right)$ for each of the isotopes described below.
a. number of protons $=27$, number of neutrons $=31$
b. the isotope of boron with mass number 10
c. $Z=12, A=23$
d. atomic number 53 , number of neutrons $=79$
e. $Z=9$, number of neutrons $=10$
f. number of protons $=29$, mass number 65

Ricardo Moreno
Ricardo Moreno
Numerade Educator
04:59

Problem 43

How many protons, neutrons, and electrons are in each of the following atoms or ions?
a. ${ }_{12}^{24} \mathrm{Mg}$
d. ${ }_{27}^{59} \mathrm{Co}^{3+}$
g. ${ }_{34}^{79} \mathrm{Se}^{2-}$
b. ${ }_{12}^{24} \mathrm{Mg}^{2+}$
e. ${ }_{27}^{59} \mathrm{Co}$
h. ${ }_{28}^{63} \mathrm{Ni}$
c. ${ }_{27}^{59} \mathrm{Co}^{2+}$
f. ${ }_3^{79} \mathrm{Se}$
i. ${ }_{28}^{59} \mathrm{Ni}^{2+}$

Kendrick Buford
Kendrick Buford
Numerade Educator
View

Problem 44

Complete the following table.
$$
\begin{array}{ccccc}
\text { Symbol } & \begin{array}{c}
\text { Number of } \\
\text { Protons in } \\
\text { Nucleus }
\end{array} & \begin{array}{c}
\text { Number of } \\
\text { Neutrons in } \\
\text { Nucleus }
\end{array} & \begin{array}{c}
\text { Number of } \\
\text { Electrons }
\end{array} & \begin{array}{c}
\text { Net } \\
\text { Charge }
\end{array} \\
\hline{ }_{92}^{238 \mathrm{U}} & - & - & - & - \\
- & 20 & 20 & - & 2+ \\
- & 23 & 28 & 20 & - \\
{ }_{39}^{89} \mathrm{Y} & - & - & - & - \\
- & 35 & 44 & 36 & - \\
- & 15 & 16 & - & 3-
\end{array}
$$

Tom Comey
Tom Comey
Numerade Educator
01:42

Problem 45

What is the symbol for an ion with 63 protons, 60 electrons, and 88 neutrons? If an ion contains 50 protons, 68 neutrons, and 48 electrons, what is its symbol?

Ly Tran
Ly Tran
Numerade Educator
04:12

Problem 46

What is the symbol of an ion with 16 protons, 18 neutrons, and 18 electrons? What is the symbol for an ion that has 16 protons, 16 neutrons, and 18 electrons?

LJ
Lena Jake
Numerade Educator
01:29

Problem 47

Would you expect each of the following atoms to gain or lose electrons when forming ions? What ion is the most likely in each case?
a. Ra
c. P
e. Br
b. In
d. Te
f. Rb

Ly Tran
Ly Tran
Numerade Educator
01:12

Problem 48

For each of the following atomic numbers, use the periodic table to write the formula (including the charge) for the simple ion that the element is most likely to form in ionic compounds.
a. 13
c. 56
e. 87
b. 34
d. 7
f. 35

Anand Jangid
Anand Jangid
Numerade Educator
03:21

Problem 49

The compounds $\mathrm{AlCl}_3, \mathrm{CrCl}_3$, and $\mathrm{ICl}_3$ have similar formulas, yet each follows a different set of rules to name it. Name these compounds, and then compare and contrast the nomenclature rules used in each case.

Kendrick Buford
Kendrick Buford
Numerade Educator
01:53

Problem 50

Each of the following compounds has three possible names listed for it. For each compound, what is the correct name and why aren't the other names used?
a. $\mathrm{N}_2 \mathrm{O}$ : nitrogen oxide, nitrogen(I) oxide, dinitrogen monoxide
b. $\mathrm{Cu}_2 \mathrm{O}$ : copper oxide, copper(I) oxide, dicopper monoxide
c. $\mathrm{Li}_2 \mathrm{O}$ : lithium oxide, lithium(I) oxide, dilithium monoxide

Bryan Li
Bryan Li
Numerade Educator
04:35

Problem 51

Name the compounds in parts a-d and write the formulas for the compounds in parts e-h.
a. $\mathrm{Hg}_2 \mathrm{O}$
e. $\operatorname{tin}($ II) nitride
b. $\mathrm{FeBr}_3$
f. cobalt(III) iodide
c. $\operatorname{CoS}$
g. mercury(II) oxide
d. $\mathrm{TiCl}_4$
h. chromium(VI) sulfide

Vishal Sharma
Vishal Sharma
Numerade Educator
01:19

Problem 52

Name the compounds in parts a-d and write the formulas for the compounds in parts e-h.
a. $\mathrm{BaSO}_3$
e. chromium(III) hydroxide
b. $\mathrm{NaNO}_2$
f. magnesium cyanide
c. $\mathrm{KMnO}_4$
g. lead(IV) carbonate
d. $\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$
h. ammonium acetate

Niamat Khuda
Niamat Khuda
Numerade Educator
02:02

Problem 53

Name each of the following compounds.
IMAGE CANT COPY

Grigoriy Sereda
Grigoriy Sereda
Numerade Educator
04:08

Problem 54

Name the following compounds.
a. $\mathrm{NaClO}_4$
e. $\mathrm{SF}_6$
i. NaOH
b. $\mathrm{Mg}_3\left(\mathrm{PO}_4\right)_2$
f. $\mathrm{Na}_2 \mathrm{HPO}_4$
j. $\mathrm{Mg}(\mathrm{OH})_2$
c. $\mathrm{Al}_2\left(\mathrm{SO}_4\right)_3$
g. $\mathrm{NaH}_2 \mathrm{PO}_4$
k. $\mathrm{Al}(\mathrm{OH})_3$
d. $\mathrm{SF}_2$
h. $\mathrm{Li}_3 \mathrm{~N}$
1. $\mathrm{Ag}_2 \mathrm{CrO}_4$

Kendrick Buford
Kendrick Buford
Numerade Educator
03:07

Problem 55

Name each of the following compounds.
a. CuI
e. $\mathrm{NaHCO}_3$
i. $\mathrm{BaCrO}_4$
b. $\mathrm{CuI}_2$
f. $\mathrm{S}_4 \mathrm{~N}_4$
j. $\mathrm{NH}_4 \mathrm{NO}_3$
c. $\mathrm{CoI}_2$
g. $\mathrm{SeBr}_4$
d. $\mathrm{Na}_2 \mathrm{CO}_3$
h. NaOCl

Ronald Prasad
Ronald Prasad
Numerade Educator
03:42

Problem 56

Name the following compounds. Assume the potential acids are dissolved in water.
a. $\mathrm{HC}_2 \mathrm{H}_3 \mathrm{O}_2$
d. ICl
b. $\mathrm{NH}_4 \mathrm{NO}_2$
e. $\mathrm{Pb}_3\left(\mathrm{PO}_4\right)_2$
c. $\mathrm{Co}_2 \mathrm{~S}_3$
f. $\mathrm{KClO}_3$
g. $\mathrm{H}_2 \mathrm{SO}_4 \quad$ j. $\mathrm{SnO}_2$
h. $\mathrm{Sr}_3 \mathrm{~N}_2$
k. $\mathrm{Na}_2 \mathrm{CrO}_4$
i. $\mathrm{Al}_2\left(\mathrm{SO}_3\right)_3$
1. HClO

Kendrick Buford
Kendrick Buford
Numerade Educator
06:05

Problem 57

Write formulas for the following compounds.
a. Sulfur dioxide
h. Tin(IV) fluoride
b. Sulfur trioxide
i. Ammonium hydrogen
c. Sodium sulfite sulfate
d. Potassium hydrogen
j. Ammonium hydrogen sulfite phosphate
e. Lithium nitride
k. Potassium perchlorate
f. Chromium(III)
1. Sodium hydride carbonate
m. Hypobromous acid
g. Chromium(II) acetate
n. Hydrobromic acid

Kendrick Buford
Kendrick Buford
Numerade Educator
03:21

Problem 58

Write formulas for the following compounds.
a. Sodium oxide
h. Copper(I) chloride
b. Sodium peroxide
i. Gallium arsenide
c. Potassium cyanide
j. Cadmium selenide
d. Copper(II) nitrate
k. Zinc sulfide
e. Silicon tetrachloride
I. Mercury(I) chloride
f. Lead(II) oxide
m. Nitrous acid
g. Lead(IV) oxide
n. Diphosphorus (common name lead pentoxide dioxide)

Kendrick Buford
Kendrick Buford
Numerade Educator
02:45

Problem 59

The common names and formulas for several substances are given below. What are the systematic names for these substances?
a. Sugar of lead $\quad \mathrm{Pb}\left(\mathrm{C}_2 \mathrm{H}_3 \mathrm{O}_2\right)_2$
b. Blue vitriol
$\mathrm{CuSO}_4$
c. Quicklime
CaO
d. Epsom salts $\quad \mathrm{MgSO}_4$
e. Milk of magnesia $\quad \mathrm{Mg}(\mathrm{OH})_2$
f. Gypsum
$\mathrm{CaSO}_4$
g. Laughing gas
$\mathrm{N}_2 \mathrm{O}$

Kendrick Buford
Kendrick Buford
Numerade Educator
04:33

Problem 60

Each of the following compounds is incorrectly named. What is wrong with each name, and what is the correct name for each compound?
a. $\mathrm{FeCl}_3$, iron chloride
b. $\mathrm{NO}_2$, nitrogen(IV) oxide
c. CaO , calcium(II) monoxide
d. $\mathrm{Al}_2 \mathrm{~S}_3$, dialuminum trisulfide
e. $\mathrm{Mg}\left(\mathrm{C}_2 \mathrm{H}_3 \mathrm{O}_2\right)_2$, manganese diacetate
f. $\mathrm{FePO}_4$, iron(II) phosphide
g. $\mathrm{P}_2 \mathrm{~S}_5$, phosphorus sulfide
h. $\mathrm{Na}_2 \mathrm{O}_2$, sodium oxide
i. $\mathrm{HNO}_3$, nitrate acid
j. $\mathrm{H}_2 \mathrm{~S}$, sulfuric acid

Kendrick Buford
Kendrick Buford
Numerade Educator
01:12

Problem 61

Name the following acids.
IMAGE CANT COPY

Ronald Prasad
Ronald Prasad
Numerade Educator
02:04

Problem 62

Chlorine has two natural isotopes: ${ }_{17}^{37} \mathrm{Cl}$ and ${ }_{15}^{35} \mathrm{Cl}$. Hydrogen reacts with chlorine to form the compound HCl . Would a given amount of hydrogen react with different masses of the two chlorine isotopes? Does this conflict with the law of definite proportion? Why or why not?

Anand Jangid
Anand Jangid
Numerade Educator
00:58

Problem 63

Label the type of bonding for each of the following.
a. FIGURE CANT COPY
b. FIGURE CANT COPY

Ly Tran
Ly Tran
Numerade Educator
03:06

Problem 64

What discoveries were made by J. J. Thomson, Henri Becquerel, and Lord Rutherford? How did Dalton's model of the atom have to be modified to account for these discoveries?

Kendrick Buford
Kendrick Buford
Numerade Educator
01:36

Problem 65

Consider the chemical reaction depicted below. Label as much as you can using the terms atom, molecule, element, compound, ionic, gas, and solid.

LJ
Lena Jake
Numerade Educator
04:24

Problem 66

Section 2.3 describes the postulates of Dalton's atomic theory. With some modifications, these postulates hold up very well regarding how we view elements, compounds, and chemical reactions today. Answer the following questions concerning Dalton's atomic theory and the modifications made today.
a. The atom can be broken down into smaller parts. What are the smaller parts?
b. How are atoms of hydrogen identical to each other, and how can they be different from each other?
c. How are atoms of hydrogen different from atoms of helium? How can H atoms be similar to He atoms?
d. How is water different from hydrogen peroxide $\left(\mathrm{H}_2 \mathrm{O}_2\right)$ even though both compounds are composed of only hydrogen and oxygen?
e. What happens in a chemical reaction, and why is mass conserved in a chemical reaction?

Kendrick Buford
Kendrick Buford
Numerade Educator
01:42

Problem 67

A sample of chloroform is found to contain 12.0 g of carbon, 106.4 g of chlorine, and 1.01 g of hydrogen. If a second sample of chloroform is found to contain 30.0 g of carbon, what is the total mass of chloroform in the second sample?

Ly Tran
Ly Tran
Numerade Educator
01:11

Problem 68

In a reaction, 34.0 g of chromium(III) oxide reacts with 12.1 g of aluminum to produce chromium and aluminum oxide. If 23.3 g of chromium is produced, what mass of aluminum oxide is produced?

LJ
Lena Jake
Numerade Educator
02:17

Problem 69

The isotope of an unknown element, X, has a mass number of 79 . The most stable ion of the isotope has 36 electrons and forms a binary compound with sodium having a formula of $\mathrm{Na}_2 \mathrm{X}$. Which of the following statements is(are) true? Correct the false statements.
a. The binary compound formed between X and fluorine will be a covalent compound.
b. The isotope of X contains 38 protons.
c. The isotope of X contains 41 neutrons.
d. The identity of X is strontium, Sr .

Kendrick Buford
Kendrick Buford
Numerade Educator
04:06

Problem 70

For each of the following ions, indicate the total number of protons and electrons in the ion. For the positive ions in the list, predict the formula of the simplest compound formed between each positive ion and the oxide ion. For the negative ions in the list, predict the formula of the simplest compound formed between each negative ion and the aluminum ion.
a. $\mathrm{Fe}^{2+}$
d. $\mathrm{Cs}^{+}$
g. $\mathrm{Br}^{-}$
b. $\mathrm{Fe}^{3+}$
e. $\mathrm{S}^{2-}$
h. $\mathrm{N}^{3-}$
c. $\mathrm{Ba}^{2+}$
f. $\mathrm{P}^{3-}$

Kendrick Buford
Kendrick Buford
Numerade Educator
00:55

Problem 71

An element's most stable ion forms an ionic compound with bromine, having the formula $\mathrm{XBr}_2$. If the ion of element X has a mass number of 230 and 86 electrons, what is the identity of the element, and how many neutrons does it have?

Ly Tran
Ly Tran
Numerade Educator
02:45

Problem 72

Using the information in Table 2.2, answer the following questions. In an ion with an unknown charge, the total mass of all the electrons was determined to be $2.55 \times$ $10^{-26} \mathrm{~g}$, while the total mass of its protons was $5.34 \times$ $10^{-23} \mathrm{~g}$. What is the identity and charge of this ion? What is the symbol and mass number of a neutral atom whose total mass of its electrons is $3.92 \times 10^{-26} \mathrm{~g}$, while its neutrons have a mass of $9.35 \times 10^{-23} \mathrm{~g}$ ?

Ly Tran
Ly Tran
Numerade Educator
02:10

Problem 73

The two most reactive families of elements are the halogens and the alkali metals. How do they differ in their reactivities?

LJ
Lena Jake
Numerade Educator
04:00

Problem 74

The early alchemists used to do an experiment in which water was boiled for several days in a sealed glass container. Eventually, some solid residue would begin to appear in the bottom of the flask. This result was interpreted to mean that some of the water in the flask had been converted into earth. When Lavoisier repeated this experiment, he found that the water weighed the same before and after heating, and the weight of the flask plus the solid residue equaled the original weight of the flask. Were the alchemists correct? Explain what really happened. (This experiment is described in the article by A.F. Scott in Scientific American, January 1984.)

Kendrick Buford
Kendrick Buford
Numerade Educator
00:34

Problem 75

Elements in the same family often form oxyanions of the same general formula. The anions are named in a similar fashion. What are the names of the oxyanions of selenium and tellurium: $\mathrm{SeO}_4{ }^{2-}, \mathrm{SeO}_3{ }^{2-}, \mathrm{TeO}_4{ }^{2-}, \mathrm{TeO}_3{ }^{2-}$ ?

Ly Tran
Ly Tran
Numerade Educator
02:16

Problem 76

How would you name $\mathrm{HBrO}_4, \mathrm{KIO}_3, \mathrm{NaBrO}_2$, and HIO ? Refer to Table 2.5 and the acid nomenclature discussion in the text.

Kendrick Buford
Kendrick Buford
Numerade Educator
03:48

Problem 77

Indium oxide contains 4.784 g of indium for every 1.000 g of oxygen. In 1869 , when Mendeleev first presented his version of the periodic table, he proposed the formula $\operatorname{In}_2 \mathrm{O}_3$ for indium oxide. Before that time, it was thought that the formula was $\operatorname{InO}$. What values for the atomic mass of indium are obtained using these two formulas? Assume that oxygen has an atomic mass of 16.00 .

LJ
Lena Jake
Numerade Educator
05:19

Problem 78

The designations 1A through 8 A used for certain families of the periodic table are helpful for predicting the charges on ions in binary ionic compounds. In these compounds, the metals generally take on a positive charge equal to the family number, and the nonmetals take on a negative charge equal to the family number minus 8 . Thus the compound formed from sodium and chlorine contains $\mathrm{Na}^{+}$and $\mathrm{Cl}^{-}$ions and has the formula NaCl . Predict the formula and the name of the binary compound formed from the following pairs of elements.
a. Ca and N
e. Ba and I
b. K and O
f. Al and Se
c. Rb and F
g. Cs and $P$
d. Mg and S
h. In and Br

Kendrick Buford
Kendrick Buford
Numerade Educator
02:07

Problem 79

Consider $100.0-\mathrm{g}$ samples of two different compounds consisting only of carbon and oxygen. One compound contains 27.2 g of carbon, and the other has 42.9 g of carbon. How can these data support the law of multiple proportions if 42.9 is not a multiple of 27.2 ? Show that these data support the law of multiple proportions.

Ricardo Moreno
Ricardo Moreno
Numerade Educator
02:51

Problem 80

Identify each of the following elements.
a. a member of the same family as oxygen whose most stable ion contains 54 electrons
b. a member of the alkali metal family whose most stable ion contains 36 electrons
c. a noble gas with 18 protons in the nucleus
d. a halogen with 85 protons and 85 electrons

LJ
Lena Jake
Numerade Educator
02:19

Problem 81

A certain element has only two naturally occurring isotopes: one with 18 neutrons and the other with 20 neutrons. The element forms 1-charged ions when in ionic compounds. Predict the identity of the element. What number of electrons does the 1 - charged ion have?

LJ
Lena Jake
Numerade Educator
01:43

Problem 82

Complete the following table.
$$
\begin{array}{|c|c|c|c|}
\hline \text { Atom/Ion } & \text { Protons } & \text { Neutrons } & \text { Electrons } \\
\hline{ }_{50}^{120} \mathrm{Sn} & & & \\
\hline{ }_{12}^{25} \mathrm{Mg}^{2+} & & & \\
\hline{ }_{26}^{56} \mathrm{Fe}^{2+} & & & \\
\hline{ }_{34}^{79} \mathrm{Se} & & & \\
\hline{ }_{17}^{35} \mathrm{Cl} & & & \\
\hline{ }_{29}^{63} \mathrm{Cu} & & \text { — } & ] \\
\hline
\end{array}
$$

Anand Jangid
Anand Jangid
Numerade Educator
01:57

Problem 83

Which of the following is(are) correct?
a. ${ }^{40} \mathrm{Ca}^{2+}$ contains 20 protons and 18 electrons.
b. Rutherford created the cathode-ray tube and was the founder of the charge-to-mass ratio of an electron.
c. An electron is heavier than a proton.
d. The nucleus contains protons, neutrons, and electrons.

Mehrnaz Siavoshi
Mehrnaz Siavoshi
Numerade Educator
04:32

Problem 84

What are the formulas of the compounds that correspond to the names given in the following table?
$$
\begin{array}{ll}
\hline \text { Compound Name } & \text { Formula } \\
\hline \text { Carbon tetrabromide } & \\
\text { Cobalt(II) phosphate } & \\
\text { Magnesium chloride } & \\
\text { Nickel(II) acetate } & \\
\hline \text { Calcium nitrate } &
\end{array}
$$

LJ
Lena Jake
Numerade Educator
04:32

Problem 85

What are the names of the compounds that correspond to the formulas given in the following table?

LJ
Lena Jake
Numerade Educator
01:03

Problem 86

Complete the following table to predict whether the given atom will gain or lose electrons in forming the ion most likely to form when in ionic compounds.
$$
\begin{array}{lcc}
\text { Atom } & \begin{array}{c}
\text { Gain (G) or Lose (L) } \\
\text { Electrons }
\end{array} & \text { Ion Formed } \\
\hline \mathrm{K} & - & \\
\mathrm{Cs} & - & - \\
\mathrm{Br} & - & - \\
\mathrm{S} & - & \\
\mathrm{Se} & - &
\end{array}
$$

Ly Tran
Ly Tran
Numerade Educator
06:50

Problem 87

Which of the following statements is(are) correct?
a. The symbols for the elements magnesium, aluminum, and xenon are $\mathrm{Mn}, \mathrm{Al}$, and Xe , respectively.
b. The elements P, As, and Bi are in the same family on the periodic table.
c. All of the following elements are expected to gain electrons to form ions in ionic compounds: $\mathrm{Ga}, \mathrm{Se}$, and Br .
d. The elements $\mathrm{Co}, \mathrm{Ni}$, and Hg are all transition elements.
e. The correct name for $\mathrm{TiO}_2$ is titanium dioxide.

Temi Ajayi
Temi Ajayi
Numerade Educator
02:00

Problem 88

Reaction of 2.0 L of hydrogen gas with 1.0 L of oxygen gas yields 2.0 L of water vapor. All gases are at the same temperature and pressure. Show how these data support the idea that oxygen gas is a diatomic molecule. Must we consider hydrogen to be a diatomic molecule to explain these results?

LJ
Lena Jake
Numerade Educator
04:29

Problem 89

Each of the statements below is true, but Dalton might have had trouble explaining some of them with his atomic theory. Give explanations for the following statements.
a. The space-filling models for ethyl alcohol and dimethyl ether are shown below.
These two compounds have the same composition by mass ( $52 \%$ carbon, $13 \%$ hydrogen, and $35 \%$ oxygen), yet the two have different melting points, boiling points, and solubilities in water.
b. Burning wood leaves an ash that is only a small fraction of the mass of the original wood.
c. Atoms can be broken down into smaller particles.
d. One sample of lithium hydride is $87.4 \%$ lithium by mass, whereas another sample of lithium hydride is $74.9 \%$ lithium by mass. However, the two samples have the same properties.

Ronald Prasad
Ronald Prasad
Numerade Educator
12:40

Problem 90

You take three compounds, each consisting of two elements ( $\mathrm{X}, \mathrm{Y}$, and/or Z ) and decompose them to their respective elements. To determine the relative masses of X , Y , and Z , you collect and weigh the elements, obtaining the following data:
$$
\begin{array}{ll}
\text { Elements in Compound } & \text { Masses of Elements } \\
\hline \text { 1. } \mathrm{X} \text { and } \mathrm{Y} & \mathrm{X}=0.4 \mathrm{~g}, \mathrm{Y}=4.2 \mathrm{~g} \\
\text { 2. } \mathrm{Y} \text { and } \mathrm{Z} & \mathrm{Y}=1.4 \mathrm{~g}, \mathrm{Z}=1.0 \mathrm{~g} \\
\text { 3. } \mathrm{X} \text { and } \mathrm{Y} & \mathrm{X}=2.0 \mathrm{~g}, \mathrm{Y}=7.0 \mathrm{~g}
\end{array}
$$
a. What are the assumptions needed to solve this problem?
b. What are the relative masses of $\mathrm{X}, \mathrm{Y}$, and Z ?
c. What are the chemical formulas of the three compounds?
d. If you decompose 21 g of compound XY , how much of each element is present?

Ronald Prasad
Ronald Prasad
Numerade Educator
02:52

Problem 91

Two elements, R and Q , combine to form two binary compounds. In the first compound, 14.0 g of R combines with 3.00 g of Q . In the second compound, 7.00 g of R combines with 4.50 g of Q . Show that these data are in accord with the law of multiple proportions. If the formula of the second compound is RQ , what is the formula of the first compound?

LJ
Lena Jake
Numerade Educator
01:55

Problem 92

A single molecule has a mass of $7.31 \times 10^{-23} \mathrm{~g}$. Provide an example of a real molecule that can have this mass.

Ronald Prasad
Ronald Prasad
Numerade Educator
00:39

Problem 93

A combustion reaction involves the reaction of a substance with oxygen gas. The complete combustion of any hydrocarbon (binary compound of carbon and hydrogen) produces carbon dioxide and water as the only products. Octane is a hydrocarbon found in gasoline. Complete combustion of octane produces 8 L of carbon dioxide for every 9 L of water vapor (both measured at the same temperature and pressure). What is the ratio of carbon atoms to hydrogen atoms in a molecule of octane?

Ly Tran
Ly Tran
Numerade Educator
View

Problem 94

You have two distinct gaseous compounds made from element X and element Y . The mass percents are as follows:
Compound I: $30.43 \% \mathrm{X}, 69.57 \% \mathrm{Y}$
Compound II: $63.64 \% \mathrm{X}, 36.36 \% \mathrm{Y}$
In their natural standard states, element X and element Y exist as gases. (Monatomic? Diatomic? Triatomic? That is for you to determine.) When you react "gas X " with "gas Y " to make the products, you get the following data (all at standard pressure and temperature):
1 volume "gas X " +2 volumes "gas Y " $\longrightarrow$
2 volumes compound I
2 volumes "gas X " +1 volume "gas Y " $\longrightarrow$
2 volumes compound II
Assume the simplest possible formulas for reactants and products in these chemical equations. Then determine the relative atomic masses of element X and element Y .

Susan Hallstrom
Susan Hallstrom
Numerade Educator
10:49

Problem 95

You have gone back in time and are working with Dalton on a table of relative masses. Following are his data:
0.602 g gas A reacts with 0.295 g gas B
0.172 g gas B reacts with 0.401 g gas C
0.320 g gas A reacts with 0.374 g gas C
a. Assuming simplest formulas ( $\mathrm{AB}, \mathrm{BC}$, and AC ), construct a table of relative masses for Dalton.
b. Knowing some history of chemistry, you tell Dalton that if he determines the volumes of the gases reacted at constant temperature and pressure, he need not assume simplest formulas. You collect the following data:
6 volumes gas $\mathrm{A}+1$ volume gas $\mathrm{B} \longrightarrow 4$ volumes product
1 volume gas $\mathrm{B}+4$ volumes gas $\mathrm{C} \longrightarrow 4$ volumes product
3 volumes gas $\mathrm{A}+2$ volumes gas $\mathrm{C} \longrightarrow 6$ volumes product
Write the simplest balanced equations, and find the actual relative masses of the elements. Explain your reasoning.

LJ
Lena Jake
Numerade Educator