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Chemistry: The Central Science in SI Units, Global Edition

Theodore L. Brown, Matthew W. Stoltzfus, Michael W. Lufaso

Chapter 16

Acid–Base Equilibria - all with Video Answers

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Chapter Questions

02:15

Problem 1

(a) Identify the Brønsted-Lowry acid and base in the reaction
(b) Identify the Lewis acid and base in the reaction.

Sima Sarker
Sima Sarker
Numerade Educator
03:36

Problem 2

The following diagrams represent aqueous solutions of two monoprotic acids, HA $(A=X$ or $Y)$. The water molecules have been omitted for clarity. (a) Which is the stronger acid, HX or HY? (b) Which is the stronger base, $X^{-}$ or $Y^{-}$ ? (c) If you mix equal concentrations of HX and NaY, will the equilibrium $$
\mathrm{HX}(a q)+\mathrm{Y}^{-}(a q) \rightleftharpoons \mathrm{HY}(a q)+\mathrm{X}^{-}(a q) $$
lie mostly to the right $\left(K_{c}>1\right)$ or to the left $\left(K_{c}<1\right) ?$ $[$ Section 16.2]

Allison Parrett
Allison Parrett
Numerade Educator
01:48

Problem 3

The indicator methyl orange has been added to both of the following solutions. Based on the colors, classify each statement as true or false:
(a) The $\mathrm{pH}$ of solution $\mathrm{A}$ is definitely less than 7.00 .
(b) The pH of solution $\mathrm{B}$ is definitely greater than $7.00 .$
(c) The pH of solution B is greater than that of solution A. $[$ Section 16.4$]$

Aadit Sharma
Aadit Sharma
Numerade Educator
04:13

Problem 4

The probe of the pH meter shown here is sitting in a beaker that contains a clear liquid. (a) You are told the liquid is pure water, a solution of $\mathrm{HCl}(a q),$ or a solution of $\mathrm{KOH}(a q)$. Which one is it? (b) If the liquid is one of the solutions, what is its molarity? (c) Why is the temperature given on the pH meter? [Sections 16.4 and 16.5$]$

Allison Parrett
Allison Parrett
Numerade Educator
02:49

Problem 5

The following diagrams represent aqueous solutions of three acids, HX, HY, and HZ. The water molecules have been omitted for clarity, and the hydrated proton is represented as $\mathrm{H}^{+}$ rather than $\mathrm{H}_{3} \mathrm{O}^{+}$. (a) Which of the acids is a strong acid? Explain. (b) Which acid would have the smallest aciddissociation constant, $K_{a} ?(\mathbf{c})$ Which solution would have the highest pH? [Sections 16.5 and 16.6$]$

Shubham Kumar
Shubham Kumar
Numerade Educator
03:09

Problem 6

The graph given below shows $\left[\mathrm{H}^{+}\right]$ versus concentration for an aqueous solution of an unknown substance. (a) Is the substance a strong acid, a weak acid, a strong base, or a weak base? (b) Based on your answer to (a), can you determine the value of the $\mathrm{pH}$ of the solution when the concentration is $0.18 \mathrm{M} ?(\mathbf{c})$ Would the line go exactly through the origin of the plot? [Sections 16.5 and 16.6$]$

Allison Parrett
Allison Parrett
Numerade Educator
01:11

Problem 7

Which of these statements about how the percent ionization of a weak acid depends on acid concentration is true?
(a) Line A is most accurate because $K_{a}$ does not depend on concentration.
(b) Line $A$ is the most accurate because the percent ionization of the acid does not depend on concentration.
(c) Line $\mathrm{B}$ is the most accurate because as the acid concentration increases, a greater proportion of it is ionized.
(d) Line $B$ is the most accurate because as the acid concentration increases, $K_{a}$ increases.
(e) Line $\mathrm{C}$ is the most accurate because as the acid concentration increases, a lesser proportion of it ionized.
(f) Line $C$ is the most accurate because as the acid concentration increases, $K_{a}$ decreases.

David Roberts
David Roberts
Numerade Educator
03:48

Problem 8

Each of the three molecules shown here contains an OH group, but one molecule acts as a base, one as an acid, and the third is neither acid nor base.
(a) Which one acts as a base? (b) Which one acts as an acid? (c) Which one is neither acidic nor basic? [Sections 16.6 and 16.7$]$

Allison Parrett
Allison Parrett
Numerade Educator
05:08

Problem 9

Phenylephrine, an organic substance with molecular formula $\mathrm{C}_{9} \mathrm{H}_{13} \mathrm{NO}_{2},$ is used as a nasal decongenstant in over-thecounter medications. The molecular structure of phenylephrine is shown below using the usual shortcut organic structure. (a) Would you expect a solution of phenylephrine to be acidic, neutral, or basic? (b) One of the active ingredients in Alka-Seltzer PLUS $^{\circ}$ cold medication is phenylephrine hydrochloride. How does this ingredient differ from the structure shown below? (c) Would you expect a solution of phenylephrine hydrochloride to be acidic, neutral, or basic? [Sections 16.8 and 16.9$]$

Susan Hallstrom
Susan Hallstrom
Numerade Educator
02:47

Problem 10

Which of the following diagrams best represents an aqueous solution of NaF? (For clarity, the water molecules are not shown.) Will this solution be acidic, neutral, or basic? $[$ Section 16.9$]$

Shubham Kumar
Shubham Kumar
Numerade Educator
05:05

Problem 11

Consider the molecular models shown here, where $X$ represents a halogen atom. (a) If $X$ is the same atom in both molecules, which molecule will be more acidic? (b) Does the acidity of each molecule increase or decrease as the electronegativity of the atom $\mathrm{X}$ increases? [Section 16.10]

Sima Sarker
Sima Sarker
Numerade Educator
02:36

Problem 12

For each of these reactions, identify the acid and base among the reactants, and state if the acids and bases are Lewis, Arrhenius, and/or Brønsted-Lowry:
(a) $\mathrm{PCl}_{4}^{+}+\mathrm{Cl}^{-} \longrightarrow \mathrm{PCl}_{5}$
(b) $\mathrm{NH}_{3}+\mathrm{BF}_{3} \longrightarrow \mathrm{H}_{3} \mathrm{NBF}_{3}$
(c) $\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}+\mathrm{H}_{2} \mathrm{O} \longrightarrow\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{5} \mathrm{OH}\right]^{2+}+\mathrm{H}_{3} \mathrm{O}^{+}$

Sima Sarker
Sima Sarker
Numerade Educator
02:05

Problem 13

$\mathrm{NH}_{3}(g)$ and $\mathrm{HCl}(g)$ react to form the ionic solid $\mathrm{NH}_{4} \mathrm{Cl}(s) .$
Which substance is the Brønsted-Lowry acid in this reaction? Which is the Brønsted-Lowry base?

Sima Sarker
Sima Sarker
Numerade Educator
02:42

Problem 14

Which of the following statements is false?
(a) An Arrhenius base increases the concentration of $\mathrm{OH}^{-}$ in water.
(b) A Brønsted-Lowry base is a proton acceptor.
(c) Water can act as a Brønsted-Lowry acid.
(d) Water can act as a Brønsted-Lowry base.
(e) Any compound that contains an -OH group acts as a Brønsted-Lowry base.

Sima Sarker
Sima Sarker
Numerade Educator
01:34

Problem 15

(a) Give the conjugate base of the following Brønsted Lowry acids: (i) $\mathrm{H}_{2} \mathrm{PO}_{4}^{-},$ (ii) HBr. (b) Give the conjugate acid of the following Bronsted-Lowry bases: (i) $\mathrm{CN}^{-},$ (ii) $\mathrm{HSO}_{4}^{-}$.

Sima Sarker
Sima Sarker
Numerade Educator
01:48

Problem 16

(a) Give the conjugate base of the following BrønstedLowry acids:
(i) $\mathrm{H}_{2} \mathrm{SO}_{3},$ (ii) $\mathrm{HSO}_{3}^{-}$ (b) Give the conjugate acid of the following Bronsted-Lowry bases: (i) $\mathrm{CH}_{3} \mathrm{NH}_{2}$,
(ii) $\mathrm{CH}_{3} \mathrm{COO}^{-}$.

Sima Sarker
Sima Sarker
Numerade Educator
02:40

Problem 17

Identify the Brønsted-Lowry acid and the Brønsted-Lowry base on the left side of each of the following equations, and also identify the conjugate acid and conjugate base of each on the right side:
(a) $\mathrm{NH}_{4}^{+}(a q)+\mathrm{CN}^{-}(a q) \rightleftharpoons \mathrm{HCN}(a q)+\mathrm{NH}_{3}(a q)$
(b) $\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons$
$$
\left(\mathrm{CH}_{3}\right)_{3} \mathrm{NH}^{+}(a q)+\mathrm{OH}^{-}(a q)
$$
(c) $\mathrm{HCOOH}(a q)+\mathrm{PO}_{4}^{3-}(a q) \rightleftharpoons$
$$
\mathrm{HCOO}^{-}(a q)+\mathrm{HPO}_{4}^{2-}(a q)
$$

Sima Sarker
Sima Sarker
Numerade Educator
02:14

Problem 18

Identify the Brønsted-Lowry acid and the BrønstedLowry base on the left side of each equation, and also identify the conjugate acid and conjugate base of each on the right side.
$$
\begin{array}{l}
\text { (a) } \mathrm{HBrO}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{BrO}^{-}(a q) \\
\text { (b) } \mathrm{HSO}_{4}^{-}(a q)+\mathrm{HCO}_{3}^{-}(a q) \rightleftharpoons \mathrm{SO}_{4}^{2-}(a q)+\mathrm{H}_{2} \mathrm{CO}_{3}(a q) \\
\text { (c) } \mathrm{HSO}_{3}^{-}(a q)+\mathrm{H}_{3} \mathrm{O}^{+}(a q) \rightleftharpoons \mathrm{H}_{2} \mathrm{SO}_{3}(a q)+\mathrm{H}_{2} \mathrm{O}(l)
\end{array}
$$

Sima Sarker
Sima Sarker
Numerade Educator
02:42

Problem 19

(a) The hydrogen carbonate ion $\left(\mathrm{HCO}_{3}^{-}\right)$ is amphiprotic. Write a balanced chemical equation showing how it acts as an acid toward water and another equation showing how it acts as a base toward water.

Sima Sarker
Sima Sarker
Numerade Educator
03:08

Problem 20

(a) Write an equation for the react ion in which $\mathrm{HSO}_{4}^{-}(a q)$ acts as a base in $\mathrm{H}_{2} \mathrm{O}(l) .(\mathbf{b})$ Write an equation for the reaction in which $\mathrm{HSO}_{4}^{-}(a q)$ acts as an acid in $\mathrm{H}_{2} \mathrm{O}(I) \cdot(\mathbf{c})$ What is the conjugate acid of $\mathrm{HSO}_{4}^{-}(a q) ?$ What is its conjugate base?

Sima Sarker
Sima Sarker
Numerade Educator
02:32

Problem 21

Label each of the following as being a strong base, a weak base, or a species with negligible basicity. In each case write the formula of its conjugate acid, and indicate whether the conjugate acid is a strong acid, a weak acid, or a species with negligible acidity: $(\mathbf{a}) \mathrm{F}^{-}(\mathbf{b}) \mathrm{Br}^{-}(\mathbf{c}) \mathrm{HS}^{-}(\mathbf{d}) \mathrm{ClO}_{4}^{-}(\mathbf{e}) \mathrm{HCOO}^{-}$

Sima Sarker
Sima Sarker
Numerade Educator
04:35

Problem 22

Label each of the following as being a strong acid, a weak acid, or a species with negligible acidity. In each case write the formula of its conjugate base, and indicate whether the conjugate base is a strong base, a weak base, or a species with negligible basicity: $(\mathbf{a}) \mathrm{HCOOH},(\mathbf{b}) \mathrm{H}_{2},(\mathbf{c}) \mathrm{CH}_{4},$
(d) $\mathrm{HF}$
(e) $\mathrm{NH}_{4}^{+}$.

Allison Parrett
Allison Parrett
Numerade Educator
01:16

Problem 23

(a) Which of the following is the stronger Bronsted-Lowry acid, HBrO or HBr? (b) Which is the stronger BronstedLowry base, $\mathrm{F}^{-}$ or $\mathrm{Cl}^{-} ?$

John Nicolle
John Nicolle
Numerade Educator
01:20

Problem 24

(a) Which of the following is the stronger Brønsted-Lowry acid, $\mathrm{HClO}_{3}$ or $\mathrm{HClO}_{2} ?$ (b) Which is the stronger Brønsted-

John Nicolle
John Nicolle
Numerade Educator
01:09

Problem 25

Predict the products of the following acid-base reactions, and predict whether the equilibrium lies to the left or to the right of the reaction arrow: (a) $\mathrm{O}^{2-}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons$
(b) $\mathrm{CH}_{3} \mathrm{COOH}(a q)+\mathrm{HS}^{-}(a q) \rightleftharpoons$
(c) $\mathrm{NO}_{2}^{-}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons$

Aadit Sharma
Aadit Sharma
Numerade Educator
05:13

Problem 26

Predict the products of the following acid-base reactions, and predict whether the equilibrium lies to the left or to the right of the reaction arrow:
(a) $\mathrm{NH}_{4}^{+}(a q)+\mathrm{OH}^{-}(a q) \rightleftharpoons$
(b) $\mathrm{CH}_{3} \mathrm{COO}^{-}(a q)+\mathrm{H}_{3} \mathrm{O}^{+}(a q) \rightleftharpoons$
(c) $\mathrm{HCO}_{3}^{-}(a q)+\mathrm{F}^{-}(a q) \rightleftharpoons$

Allison Parrett
Allison Parrett
Numerade Educator
01:56

Problem 27

If a neutral solution of water, with $\mathrm{pH}=7.00,$ is cooled to $10^{\circ} \mathrm{C},$ the pH rises to $7.27 .$ Which of the following three statements is correct for the cooled water: (i) $\left[\mathrm{H}^{+}\right]>\left[\mathrm{OH}^{-}\right]$
(ii) $\left[\mathrm{H}^{+}\right]=\left[\mathrm{OH}^{-}\right], \mathrm{or}$
(iii) $\left[\mathrm{H}^{+}\right]<\left[\mathrm{OH}^{-}\right] ?$

Aadit Sharma
Aadit Sharma
Numerade Educator
02:46

Problem 28

(a) Write a chemical equation that illustrates the autoionization of water. (b) Write the expression for the ionproduct constant for water, $K_{w} .(\mathbf{c})$ If a solution is described as basic, which of the following is true: (i) $\left[\mathrm{H}^{+}\right]>\left[\mathrm{OH}^{-}\right]$,
(ii) $\left[\mathrm{H}^{+}\right]=\left[\mathrm{OH}^{-}\right],$ or (iii) $\left[\mathrm{H}^{+}\right]<\left[\mathrm{OH}^{-}\right] ?$

Sima Sarker
Sima Sarker
Numerade Educator
04:54

Problem 29

Calculate $\left[\mathrm{H}^{+}\right]$ for each of the following solutions, and indicate whether the solution is acidic, basic, or neutral:
(a) $\left[\mathrm{OH}^{-}\right]=7.3 \times 10^{-10} \mathrm{M}(\mathbf{b})\left[\mathrm{OH}^{-}\right]=0.015 \mathrm{M} ;$
(c) a solution in which $\left[\mathrm{H}^{+}\right]$ is 10 times greater than $\left[\mathrm{OH}^{-}\right]$.

Sima Sarker
Sima Sarker
Numerade Educator
04:24

Problem 30

Calculate $\left[\mathrm{OH}^{-}\right]$ for each of the following solutions, and indicate whether the solution is acidic, basic, or neutral:
(a) $\left[\mathrm{H}^{+}\right]=0.00010 \mathrm{M} ;(\mathbf{b})\left[\mathrm{H}^{+}\right]=7.3 \times 10^{-14} \mathrm{M} ;(\mathbf{c})$ a solution in which $\left[\mathrm{OH}^{-}\right]$ is 100 times greater than $\left[\mathrm{H}^{+}\right]$.

Sima Sarker
Sima Sarker
Numerade Educator
02:24

Problem 31

At the boiling point of water $\left(100^{\circ} \mathrm{C}\right), K_{w}=5.6 \times 10^{-13} .$ Calculate $\left[\mathrm{H}^{+}\right]$ and $\left[\mathrm{OH}^{-}\right]$ for a neutral solution at this temperature.

Sima Sarker
Sima Sarker
Numerade Educator
02:15

Problem 32

Deuterium oxide $\left(\mathrm{D}_{2} \mathrm{O},\right.$ where $\mathrm{D}$ is deuterium, the hydrogen- 2 isotope) has an ion-product constant, $K_{w}$, of $8.9 \times 10^{-16}$ at $20^{\circ} \mathrm{C}$. Calculate $\left[\mathrm{D}^{+}\right]$ and $\left[\mathrm{OD}^{-}\right]$ for pure (neutral) $\mathrm{D}_{2} \mathrm{O}$ at this temperature.

Allison Parrett
Allison Parrett
Numerade Educator
02:45

Problem 33

By what factor does $\left[\mathrm{H}^{+}\right]$ change for a pH change of
(a) 3.0 units,
(b) 0.3 units?

AA
Angelina Azieva
Numerade Educator
02:16

Problem 34

Consider two solutions, solution A and solution B. [H $\left.^{+}\right]$ in solution A is 25 times greater than that in solution $B$. What is the difference in the pH values of the two solutions?

John Nicolle
John Nicolle
Numerade Educator
07:54

Problem 35

Complete the following table by calculating the missing entries and indicating whether the solution is acidic or basic. Consider the temperature to be $25^{\circ} \mathrm{C}$.

Sima Sarker
Sima Sarker
Numerade Educator
09:56

Problem 36

Complete the following table by calculating the missing entries. In each case, indicate whether the solution is acidic or basic.

Allison Parrett
Allison Parrett
Numerade Educator
02:25

Problem 37

The average $\mathrm{pH}$ of normal arterial blood is 7.40 . At normal body temperature $\left(37^{\circ} \mathrm{C}\right), K_{w}=2.4 \times 10^{-14} .$ Calculate $\left[\mathrm{H}^{+}\right],\left[\mathrm{OH}^{-}\right]$, and $\mathrm{pOH}$ for blood at this temperature.

Aadit Sharma
Aadit Sharma
Numerade Educator
03:36

Problem 38

Carbon dioxide in the atmosphere dissolves in raindrops to produce carbonic acid $\left(\mathrm{H}_{2} \mathrm{CO}_{3}\right)$, causing the pH of clean, unpolluted rain to range from about 5.2 to 5.6 . What are the ranges of $\left[\mathrm{H}^{+}\right]$ and $\left[\mathrm{OH}^{-}\right]$ in the raindrops?

Allison Parrett
Allison Parrett
Numerade Educator
03:37

Problem 39

Addition of the indicator methyl orange to an unknown solution leads to a yellow color. The addition of bromthymol blue to the same solution also leads to a yellow color.
(a) Is the solution acidic, neutral, or basic?
(b) What is the range (in whole numbers) of possible pH values for the solution? (c) Is there another indicator you could use to narrow the range of possible pH values for the solution?

Aadit Sharma
Aadit Sharma
Numerade Educator
04:25

Problem 40

Addition of phenolphthalein to an unknown colorless solution does not cause a color change. The addition of bromthymol blue to the same solution leads to a yellow color. (a) Is the solution acidic, neutral, or basic? (b) Which of the following can you establish about the solution: (i) A minimum $\mathrm{pH}$, (ii) A maximum $\mathrm{pH}$, or (iii) A specific range of pH values? (c) What other indicator or indicators would you want to use to determine the $\mathrm{pH}$ of the solution more precisely?

Allison Parrett
Allison Parrett
Numerade Educator
01:55

Problem 41

Is each of the following statements true or false? (a) All strong acids contain one or more H atoms.
(b) A strong acid is a strong electrolyte.
(c) A 1.0-M solution of a strong acid will have $\mathrm{pH}=1.0$

Aadit Sharma
Aadit Sharma
Numerade Educator
03:57

Problem 42

Determine whether each of the following is true or false:
(a) All strong bases are salts of the hydroxide ion. (b) The addition of a strong base to water produces a solution of $\mathrm{pH}>7.0$
(c) Because $\mathrm{Mg}(\mathrm{OH})_{2}$ is not very soluble, it cannot be a strong base.

Allison Parrett
Allison Parrett
Numerade Educator
06:32

Problem 43

Calculate the $\mathrm{pH}$ of each of the following strong acid solutions:
(a) $8.3 \times 10^{-4} \mathrm{MHCl},(\mathbf{b}) 1.20 \mathrm{~g}$ of $\mathrm{HNO}_{3}$ in $500 \mathrm{~mL}$ of solution, $(\mathbf{c}) 2.0 \mathrm{~mL}$ of $0.250 \mathrm{M} \mathrm{HClO}_{4}$ diluted to $40.0 \mathrm{~mL}$, (d) a solution formed by mixing $25.0 \mathrm{~mL}$ of $0.100 \mathrm{M} \mathrm{HBr}$ with $25.0 \mathrm{~mL}$ of $0.200 \mathrm{M} \mathrm{HCl}$.

Sima Sarker
Sima Sarker
Numerade Educator
10:13

Problem 44

Calculate the pH of each of the following strong acid solutions: $(\mathbf{a}) 0.0178 \mathrm{M} \mathrm{HNO}_{3},(\mathbf{b}) 0.500 \mathrm{~g}$ of $\mathrm{HClO}_{3}$ in $5.00 \mathrm{~L}$
of solution, $(\mathbf{c}) 5.00 \mathrm{~mL}$ of $2.00 \mathrm{M} \mathrm{HCl}$ diluted to $0.500 \mathrm{~L}$, (d) a mixture formed by adding $75.0 \mathrm{~mL}$ of $0.010 \mathrm{M} \mathrm{HCl}$ to $125 \mathrm{~mL}$ of $0.020 \mathrm{M} \mathrm{HBr}$.

Allison Parrett
Allison Parrett
Numerade Educator
08:27

Problem 45

Calculate $\left[\mathrm{OH}^{-}\right]$ and $\mathrm{pH}$ for (a) $1.5 \times 10^{-3} \mathrm{MSr}(\mathrm{OH})_{2},$ (b) $2.250 \mathrm{~g}$ of $\mathrm{LiOH}$ in $250.0 \mathrm{~mL}$ of solution, $(\mathbf{c}) 1.00$ $\mathrm{mL}$ of $0.175 \mathrm{M} \mathrm{NaOH}$ diluted to $2.00 \mathrm{~L},(\mathbf{d})$ a solution formed by adding $5.00 \mathrm{~mL}$ of $0.105 \mathrm{M} \mathrm{KOH}$ to $15.0 \mathrm{~mL}$ of $9.5 \times 10^{-2} \mathrm{MCa}(\mathrm{OH})_{2}$

Sima Sarker
Sima Sarker
Numerade Educator
14:08

Problem 46

Calculate $\left[\mathrm{OH}^{-}\right]$ and $\mathrm{pH}$ for each of the following strong base solutions: (a) $0.182 \mathrm{M} \mathrm{KOH},$ (b) $3.165 \mathrm{~g}$ of $\mathrm{KOH}$ in 500.0
$\mathrm{mL}$ of solution, $(\mathbf{c}) 10.0 \mathrm{~mL}$ of $0.0105 \mathrm{M} \mathrm{Ca}(\mathrm{OH})_{2}$ diluted to $500.0 \mathrm{~mL},(\mathbf{d})$ a solution formed by mixing $20.0 \mathrm{~mL}$ of 0.015 $M \mathrm{Ba}(\mathrm{OH})_{2}$ with $40.0 \mathrm{~mL}$ of $8.2 \times 10^{-3} \mathrm{M} \mathrm{NaOH}$.

Allison Parrett
Allison Parrett
Numerade Educator
02:07

Problem 47

Calculate the concentration of an aqueous solution of $\mathrm{NaOH}$ that has a pH of $12.70 .$

Sima Sarker
Sima Sarker
Numerade Educator
02:52

Problem 48

Calculate the concentration of an aqueous solution of $\mathrm{Ca}(\mathrm{OH})_{2}$ that has a pH of $10.05 .$.

Allison Parrett
Allison Parrett
Numerade Educator
04:08

Problem 49

Write the chemical equation and the $K_{a}$ expression for the dissociation of each of the following acids in aqueous solution. First show the reaction with $\mathrm{H}^{+}(a q)$ as a product and then with the hydronium ion: $(\mathbf{a}) \mathrm{HNO}_{2},$ (b) $\mathrm{ClH}_{2} \mathrm{CCOOH}$.

Sima Sarker
Sima Sarker
Numerade Educator
03:07

Problem 50

Write the chemical equation and the $K_{a}$ expression for the acid dissociation of each of the following acids in aqueous solution. First show the reaction with $\mathrm{H}^{+}(a q)$ as a product and then with the hydronium ion: (a) $\mathrm{HSO}_{4}^{-}$, (b) $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{OH}$.

Sima Sarker
Sima Sarker
Numerade Educator
02:13

Problem 51

Lactic acid $\left(\mathrm{CH}_{3} \mathrm{CH}(\mathrm{OH}) \mathrm{COOH}\right)$ has one acidic hydrogen. A $0.10 \mathrm{M}$ solution of lactic acid has a pH of 2.44. Calculate $K_{a}$

Aadit Sharma
Aadit Sharma
Numerade Educator
06:14

Problem 52

Phenylacetic acid $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{COOH}\right)$ is one of the substances that accumulates in the blood of people with phenylketonuria, an inherited disorder that can cause mental retardation or even death. A $0.085 \mathrm{M}$ solution of $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{COOH}$ has a pH of 2.68. Calculate the $K_{a}$ value for this acid.

Allison Parrett
Allison Parrett
Numerade Educator
04:29

Problem 53

A $0.100 \mathrm{M}$ solution of cyanic acid (HCNO) is $5.9 \%$ ionized. Using this information, calculate [CNO^ $\left.^{-}\right],\left[\mathrm{H}^{+}\right],[\mathrm{HCNO}],$ and $K_{a}$ for cyanic acid.

Sima Sarker
Sima Sarker
Numerade Educator
04:25

Problem 54

A $0.100 \mathrm{M}$ solution of bromoacetic acid $\left(\mathrm{BrCH}_{2} \mathrm{COOH}\right)$ is 13.2\% ionized. Calculate $\left[\mathrm{H}^{+}\right],\left[\mathrm{BrCH}_{2} \mathrm{COO}^{-}\right],\left[\mathrm{BrCH}_{2} \mathrm{COOH}\right]$ and $K_{a}$ for bromoacetic acid.

Shubham Kumar
Shubham Kumar
Numerade Educator
05:38

Problem 55

A particular sample of vinegar has a pH of 2.20 . If acetic acid is the only acid that vinegar contains $\left(K_{a}=1.8 \times 10^{-5}\right)$, calculate the concentration of acetic acid in the vinegar.

Sima Sarker
Sima Sarker
Numerade Educator
04:34

Problem 56

If a solution of hydrofluoric acid $\left(\mathrm{HF} ; K_{a}=6.8 \times 10^{-4}\right)$ has a $\mathrm{pH}$ of 2.12 , calculate the concentration of hydrofluoric acid.

Sima Sarker
Sima Sarker
Numerade Educator
04:34

Problem 57

The acid-dissociation constant for benzoic acid $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}\right)$ is $6.3 \times 10^{-5}$. Calculate the equilibrium concentrations of $\mathrm{H}_{3} \mathrm{O}^{+}, \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COO}^{-},$ and $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}$ in the solution if the initial concentration of $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}$ is $0.100 \mathrm{M}$.

Sima Sarker
Sima Sarker
Numerade Educator
04:35

Problem 58

The acid-dissociation constant for chlorous acid $\left(\mathrm{HClO}_{2}\right)$ is $1.1 \times 10^{-2}$. Calculate the concentrations of $\mathrm{H}_{3} \mathrm{O}^{+}, \mathrm{ClO}_{2}^{-}$, and $\mathrm{HClO}_{2}$ at equilibrium if the initial concentration of $\mathrm{HClO}_{2}$ is $0.0200 \mathrm{M}$

Sima Sarker
Sima Sarker
Numerade Educator
09:57

Problem 59

Calculate the pH of each of the following solutions $\left(K_{a}\right.$ and $K_{b}$ values are given in Appendix D):
(a) $0.150 \mathrm{M}$ propionic acid $\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{COOH}\right)$
(b) $0.250 \mathrm{M}$ hydrogen chromate ion $\left(\mathrm{HCrO}_{4}^{-}\right),(\mathbf{c}) 0.750 \mathrm{M}$ pyridine $\left(\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{~N}\right)$

Sima Sarker
Sima Sarker
Numerade Educator
13:21

Problem 60

Determine the $\mathrm{pH}$ of each of the following solutions $\left(K_{a}\right.$ and $K_{b}$ values are given in Appendix D):
(a) $0.095 \mathrm{M}$ hypochlorous acid, $(\mathbf{b}) 0.0085 \mathrm{M}$ hydrazine,
(c) $0.165 \mathrm{M}$ hydroxylamine.

Allison Parrett
Allison Parrett
Numerade Educator
04:34

Problem 61

Saccharin, a sugar substitute, is a weak acid with $\mathrm{p} K_{a}=2.32$ at $25^{\circ} \mathrm{C}$. It ionizes in aqueous solution as follows:
$$ \mathrm{HNC}_{7} \mathrm{H}_{4} \mathrm{SO}_{3}(a q) \rightleftharpoons \mathrm{H}^{+}(a q)+\mathrm{NC}_{7} \mathrm{H}_{4} \mathrm{SO}_{3}^{-}(a q) $$
What is the pH of a $0.25 \mathrm{M}$ solution of this substance?

Sima Sarker
Sima Sarker
Numerade Educator
View

Problem 62

The active ingredient in aspirin is acetylsalicylic acid $\left(\mathrm{HC}_{9} \mathrm{H}_{7} \mathrm{O}_{4}\right),$ a monoprotic acid with $K_{a}=3.3 \times 10^{-4}$ at $25^{\circ} \mathrm{C}$
What is the $\mathrm{pH}$ of a solution obtained by dissolving one regular aspirin tablet, containing $100 \mathrm{mg}$ of acetylsalicylic acid, in $200 \mathrm{~mL}$ of water?

Tom Comey
Tom Comey
Numerade Educator
04:39

Problem 63

Calculate the percent ionization of hydrazoic acid $\left(\mathrm{HN}_{3}\right)$ in solutions of each of the following concentrations $\left(K_{a}\right.$ is (c) $0.0400 \mathrm{M}$. given in Appendix $\mathrm{D}):(\mathbf{a}) 0.400 \mathrm{M},(\mathbf{b}) 0.100 \mathrm{M}$

John Nicolle
John Nicolle
Numerade Educator
09:17

Problem 64

Calculate the percent ionization of propionic acid $\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{COOH}\right)$ in solutions of each of the following concentrations $\left(K_{a}\right.$ isgiven in AppendixD):
(a) $0.250 M,(\mathbf{b}) 0.0800 M$ (c) $0.0200 \mathrm{M}$

Allison Parrett
Allison Parrett
Numerade Educator
03:03

Problem 65

Citric acid, which is present in citrus fruits, is a triprotic acid (Table 16.3). (a) Calculate the pH of a $0.040 \mathrm{M}$ solution of citric acid. (b) Did you have to make any approximations or assumptions in completing your calculations? (c) Is the concentration of citrate ion $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{O}_{7}{ }^{3-}\right)$ equal to, less than, or greater than the $\mathrm{H}^{+}$ ion concentration?

Aadit Sharma
Aadit Sharma
Numerade Educator
10:15

Problem 66

Tartaric acid is found in many fruits, including grapes, and is partially responsible for the dry texture of certain wines. Calculate the $\mathrm{pH}$ and the tartrate ion $\left(\mathrm{C}_{4} \mathrm{H}_{4} \mathrm{O}_{6}^{2-}\right)$ concentration for a $0.250 M$ solution of tartaric acid, for which the acid-dissociation constants are listed in Table 16.3. Did you have to make any approximations or assumptions in your calculation?

Allison Parrett
Allison Parrett
Numerade Educator
03:04

Problem 67

Consider the base hydroxylamine, $\mathrm{NH}_{2} \mathrm{OH}$. (a) What is the conjugate acid of hydroxylamine? (b) When it acts as a base, which atom in hydroxylamine accepts a proton?
(c) There are two atoms in hydroxylamine that have nonbonding electron pairs that could act as proton acceptors. Use Lewis structures and formal charges 000 (Section 8.5 ) to rationalize why one of these two atoms is a much better proton acceptor than the other.

John Nicolle
John Nicolle
Numerade Educator
04:10

Problem 68

The hypochlorite ion, $\mathrm{ClO}^{-}$, acts as a weak base.
(a) Is ClO a stronger or weaker base than hydroxylamine?
(b) When $\mathrm{ClO}^{-}$ acts as a base, which atom, $\mathrm{Cl}$ or $\mathrm{O}$, acts as the proton acceptor? (c) Can you use formal charges to rationalize your answer to part (b)?

Allison Parrett
Allison Parrett
Numerade Educator
02:19

Problem 69

Write the chemical equation and the $K_{b}$ expression for the reaction of each of the following bases with water: (a) trimethylamine, $\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N} ;$ (b) sulfite, $\mathrm{SO}_{3}^{2-}$;
(c) cyanide, $\mathrm{CN}^{-}$.

Sima Sarker
Sima Sarker
Numerade Educator
03:35

Problem 70

Write the chemical equation and the $K_{b}$ expression for the reaction of each of the following bases with water: (a) propylamine, $\mathrm{C}_{3} \mathrm{H}_{7} \mathrm{NH}_{2} ;$ (b) monohydrogen phosphate ion, $\mathrm{HPO}_{4}^{2-} ;(\mathbf{c})$ benzoate ion, $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CO}_{2}^{-}$

Allison Parrett
Allison Parrett
Numerade Educator
06:20

Problem 71

Calculate the molar concentration of $\mathrm{OH}^{-}$ in a $0.050 \mathrm{M}$ solution of ethylamine $\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{NH}_{2} ; K_{b}=6.4 \times 10^{-4}\right) .$ Calculate
the $\mathrm{pH}$ of this solution.

Sima Sarker
Sima Sarker
Numerade Educator
04:18

Problem 72

Calculate the molar concentration of $\mathrm{OH}^{-}$ in a $0.724 \mathrm{M}$ solution of hypobromite ion $\left(\mathrm{BrO}^{-} ; K_{b}=4.0 \times 10^{-6}\right) .$ What is the $\mathrm{pH}$ of this solution?

Allison Parrett
Allison Parrett
Numerade Educator
05:11

Problem 73

Ephedrine, a central nervous system stimulant, is used in nasal sprays as a decongestant. This compound is a weak organic base:
$$
\mathrm{C}_{10} \mathrm{H}_{15} \mathrm{ON}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{C}_{10} \mathrm{H}_{15} \mathrm{ONH}^{+}(a q)+\mathrm{OH}^{-}(a q)
$$
A $0.035 \mathrm{M}$ solution of ephedrine has a $\mathrm{pH}$ of 11.33 .
(a) What are the equilibrium concentrations of $\mathrm{C}_{10} \mathrm{H}_{15} \mathrm{ON}, \mathrm{C}_{10} \mathrm{H}_{15} \mathrm{ONH}^{+},$ and $\mathrm{OH}^{-} ?$
(b) Calculate $K_{b}$ for ephedrine.

Aadit Sharma
Aadit Sharma
Numerade Educator
03:49

Problem 74

Codeine $\left(\mathrm{C}_{18} \mathrm{H}_{21} \mathrm{NO}_{3}\right)$ is a weak organic base. A $5.0 \times 10^{-3} \mathrm{M}$ solution of codeine has a pH of 9.95. Calculate the value of $K_{b}$ for this substance. What is the $\mathrm{p} K_{b}$ for this base?

Shubham Kumar
Shubham Kumar
Numerade Educator
03:03

Problem 75

Phenol, $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{OH},$ has a $K_{a}$ of $1.3 \times 10^{-10}$
(a) Write out the $K_{a}$ reaction for phenol.
(b) Calculate $K_{b}$ for phenol's conjugate base.
(c) Is phenol a stronger or weaker acid than water?

Aadit Sharma
Aadit Sharma
Numerade Educator
02:37

Problem 76

Use the acid-dissociation constants in Table 16.3 to arrange these oxyanions from strongest base to weakest:
$\mathrm{SO}_{4}^{2-}, \mathrm{CO}_{3}^{2-}, \mathrm{SO}_{3}^{2-},$ and $\mathrm{PO}_{4}^{3-}$

Allison Parrett
Allison Parrett
Numerade Educator
03:29

Problem 77

(a) Given that $K_{a}$ for cyanic acid is $3.5 \times 10^{-4}$ and that for hydrofluoric acid is $6.8 \times 10^{-4},$ which is the stronger acid? (b) Which is the stronger base, the cyanate ion or the fluoride ion? (c) Calculate $K_{b}$ values for $\mathrm{NCO}^{-}$ and $\mathrm{F}^{-}$.

Sima Sarker
Sima Sarker
Numerade Educator
02:52

Problem 78

(a) Given that $K_{b}$ for ammonia is $1.8 \times 10^{-5}$ and that for hydroxylamine is $1.1 \times 10^{-8}$, which is the stronger base? (b) Which is the stronger acid, the ammonium ion or the hydroxylammonium ion? (c) Calculate $K_{a}$ values for $\mathrm{NH}_{4}^{+}$ and $\mathrm{H}_{3} \mathrm{NOH}^{+}$.

Allison Parrett
Allison Parrett
Numerade Educator
11:22

Problem 79

Using data from Appendix $D$, calculate $p O H$ and $p H$ for each
(a) $0.080 M$ potassium hypobromite of the following solutions:
$(\mathrm{KBrO}),$ (b) $0.150 \mathrm{M}$ potassium hydrosulfide $(\mathrm{KHS}),(\mathbf{c})$ a mixture that is $0.25 \mathrm{M}$ in potassium nitrite $\left(\mathrm{KNO}_{2}\right)$ and $0.15 \mathrm{M}$ in magnesium nitrite $\left(\mathrm{Mg}\left(\mathrm{NO}_{2}\right)_{2}\right)$.

Susan Hallstrom
Susan Hallstrom
Numerade Educator
12:49

Problem 80

Using data from Appendix D, calculate [OH^{-} ] \text { and pH }
for each of the following solutions:
(a) $0.105 \mathrm{M} \mathrm{NaF}$,
(b) $0.035 \mathrm{M} \mathrm{Na}_{2} \mathrm{~S}$
(c) a mixture that is $0.045 \mathrm{M}$ in $\mathrm{NaCH}_{3} \mathrm{COO}$ and $0.055 \mathrm{M}$ in $\mathrm{Ba}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}$

Allison Parrett
Allison Parrett
Numerade Educator
05:53

Problem 81

A solution of potassium $\left(\mathrm{KCH}_{3} \mathrm{COO}\right)$ has a pH of $8.90 .$ What is the molarity of the solution?

Sima Sarker
Sima Sarker
Numerade Educator
12:25

Problem 82

Pyridinium bromide $\left(\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{NHBr}\right)$ is a strong electrolyte that dissociates completely into $\mathrm{C}_{5} \mathrm{H}_{5} \mathrm{NH}^{+}$ and $\mathrm{Br}^{-}$. An aqueous solution of pyridinium bromide has a pH of $2.95 .$
(a) Write out the reaction that leads to this acidic pH.
(b) Using Appendix D, calculate the $K_{a}$ for pyridinium bromide.
(c) A solution of pyridinium bromide has a pH of 2.95 . What is the concentration of the pyridinium cation at equilibrium, in units of molarity?

Allison Parrett
Allison Parrett
Numerade Educator
03:24

Problem 83

Predict whether aqueous solutions of the following compounds are acidic, basic, or neutral: $(\mathbf{a}) \mathrm{NH}_{4} \mathrm{Br},(\mathbf{b}) \mathrm{FeCl}_{3},$
(c) $\mathrm{Na}_{2} \mathrm{CO}_{3}$
(e) $\mathrm{NaHC}_{2} \mathrm{O}_{4}$.
(d) $\mathrm{KClO}_{4}$,

John Nicolle
John Nicolle
Numerade Educator
04:17

Problem 84

Predict whether aqueous solutions of the following substances are acidic, basic, or neutral: (a) $\mathrm{AlCl}_{3},(\mathbf{b}) \mathrm{NaBr},$
(c) $\mathrm{NaClO},(\mathbf{d})\left[\mathrm{CH}_{3} \mathrm{NH}_{3}\right] \mathrm{NO}_{3},$
(e) $\mathrm{Na}_{2} \mathrm{SO}_{3}$

Shubham Kumar
Shubham Kumar
Numerade Educator
03:22

Problem 85

An unknown salt is either $\mathrm{NaF}, \mathrm{NaCl}$, or $\mathrm{NaOCl}$. When 0.050 mol of the salt is dissolved in water to form 0.500 L of solution, the pH of the solution is 8.08 . What is the identity of the salt?

Aadit Sharma
Aadit Sharma
Numerade Educator
03:01

Problem 86

An unknown salt is either $\mathrm{KBr}, \mathrm{NH}_{4} \mathrm{Cl}, \mathrm{KCN},$ or $\mathrm{K}_{2} \mathrm{CO}_{3} .$ If a $0.100 \mathrm{M}$ solution of the salt is neutral, what is the identity of the salt?

Allison Parrett
Allison Parrett
Numerade Educator
05:02

Problem 87

Predict the stronger acid in each pair: (a) $\mathrm{HNO}_{3}$ or HNO $_{2}$
(b) $\mathrm{H}_{2} \mathrm{~S}$ or $\mathrm{H}_{2} \mathrm{O} ;$
; (c) $\mathrm{H}_{2} \mathrm{SO}_{4}$ or $\mathrm{H}_{2} \mathrm{SeO}_{4}$
(d) $\mathrm{CH}_{3} \mathrm{COOH}$ or $\mathrm{CCl}_{3}$
?OOH.

Sima Sarker
Sima Sarker
Numerade Educator
02:07

Problem 88

Predict the stronger acid in each pair: (a) $\mathrm{HCl}$ or HF;
(b) $\mathrm{H}_{3} \mathrm{PO}_{4}$ or $\mathrm{H}_{3} \mathrm{AsO}_{4} ;$
(c) $\mathrm{HBrO}_{3}$ or $\mathrm{HBrO}_{2}$
(d) $\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}$ or
$\mathrm{HC}_{2} \mathrm{O}_{4} \overline{;} ;(\mathbf{e})$ benzoic acid $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}\right)$ or phenol $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{OH}\right) .$

John Nicolle
John Nicolle
Numerade Educator
03:30

Problem 89

Based on their compositions and structures and on conjugate acid-base relationships, select the stronger base in each of the following pairs: (a) $\mathrm{BrO}^{-}$ or $\mathrm{ClO}^{-},(\mathbf{b}) \mathrm{BrO}^{-}$ or $\mathrm{BrO}_{2}^{-}$, (c) $\mathrm{HPO}_{4}^{2-}$ or $\mathrm{H}_{2} \mathrm{PO}_{4}^{-}$.

Aadit Sharma
Aadit Sharma
Numerade Educator
02:38

Problem 90

Based on their compositions and structures and on conjugate acid-base relationships, select the stronger base in each of the following pairs:
(a) $\mathrm{NO}_{3}^{-}$ or $\mathrm{NO}_{2}^{-},$ (b) $\mathrm{PO}_{4}^{3-}$ or $\mathrm{AsO}_{4}^{3-}$,
(c) $\mathrm{HCO}_{3}^{-}$ or $\mathrm{CO}_{3}^{2-}$.

Allison Parrett
Allison Parrett
Numerade Educator
01:26

Problem 91

Indicate whether each of the following statements is true or false. For each statement that is false, correct the statement to make it true. (a) In general, the acidity of binary acids increases from left to right in a given row of the periodic table. (b) In a series of acids that have the same central atom, acid strength increases with the number of hydrogen atoms bonded to the central atom. (c) Hydrotelluric acid $\left(\mathrm{H}_{2} \mathrm{Te}\right)$ is a stronger acid than $\mathrm{H}_{2} \mathrm{~S}$ because Te is more electronegative than $\mathrm{S}$.

Aadit Sharma
Aadit Sharma
Numerade Educator
03:39

Problem 92

Indicate whether each of the following statements is true or false. For each statement that is false, correct the statement to make it true. (a) Acid strength in a series of $\mathrm{H}-\mathrm{A}$ molecules increases with increasing size of A. (b) For acids of the same general structure but differing electronegativities of the central atoms, acid strength decreases with increasing electronegativity of the central atom. (c) The strongest acid known is HF because fluorine is the most electronegative element.

Allison Parrett
Allison Parrett
Numerade Educator
03:31

Problem 93

Ammonia, $\mathrm{NH}_{3}$, acts as an Arrhenius base, a Brønsted-Lowry base, and a Lewis base, in aqueous solution. Write out the reaction $\mathrm{NH}_{3}$ undergoes with water and explain what properties of ammonia correspond to each of the three definitions of "base."

Sima Sarker
Sima Sarker
Numerade Educator
03:46

Problem 94

The fluoride ion reacts with water to produce HE.
(a) Write out the chemical equation for this reaction.
(b) Will a concentrated solution of NaF in water be acidic, basic, or neutral?
(c) Is fluoride acting as a Lewis acid or as a Lewis base when reacting with water?

Sima Sarker
Sima Sarker
Numerade Educator
02:11

Problem 95

Identify the Lewis acid and Lewis base among the reactants in each of the following reactions:
(a) $\mathrm{Fe}\left(\mathrm{ClO}_{4}\right)_{3}(s)+6 \mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons$
$$
\left[\mathrm{Fe}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{3+}(a q)+3 \mathrm{ClO}_{4}^{-}(a q)
$$
(b) $\mathrm{CN}^{-}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{HCN}(a q)+\mathrm{OH}^{-}(a q)$
(c) $\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}(g)+\mathrm{BF}_{3}(g) \rightleftharpoons\left(\mathrm{CH}_{3}\right)_{3} \mathrm{NBF}_{3}(s)$
(d) $\mathrm{HIO}(l q)+\mathrm{NH}_{2}^{-}(l q) \rightleftharpoons \mathrm{NH}_{3}(l q)+\mathrm{IO}^{-}(l q)$ (lg denotes liquid ammonia as solvent)

Sima Sarker
Sima Sarker
Numerade Educator
03:09

Problem 96

Identify the Lewis acid and Lewis base in each of the following reactions:
(a) $\mathrm{HNO}_{2}(a q)+\mathrm{OH}^{-}(a q) \rightleftharpoons \mathrm{NO}_{2}^{-}(a q)+\mathrm{H}_{2} \mathrm{O}(l)$
(b) $\mathrm{FeBr}_{3}(s)+\mathrm{Br}^{-}(a q) \rightleftharpoons \mathrm{FeBr}_{4}^{-}(a q)$
(c) $\mathrm{Zn}^{2+}(a q)+4 \mathrm{NH}_{3}(a q) \rightleftharpoons \mathrm{Zn}\left(\mathrm{NH}_{3}\right)_{4}^{2+}(a q)$
(d) $\mathrm{SO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{H}_{2} \mathrm{SO}_{3}(a q)$

Allison Parrett
Allison Parrett
Numerade Educator
02:03

Problem 97

Predict which member of each pair produces the more acidic aqueous solution:
(a) $\mathrm{K}^{+}$ or $\mathrm{Cu}^{2+}$,
(b) $\mathrm{Fe}^{2+}$ or $\mathrm{Fe}^{3+}$
(c) $\mathrm{Al}^{3+}$ or $\mathrm{Ga}^{3+}$

Aadit Sharma
Aadit Sharma
Numerade Educator
03:25

Problem 98

Which member of each pair produces the more acidic aqueous solution: $(\mathbf{a}) \mathrm{Zn} \mathrm{Br}_{2}$ or $\mathrm{CdCl}_{2},$ (b) $\mathrm{CuCl}$ or $\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}$, (c) $\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}$ or $\mathrm{NiBr}_{2} ?$

Allison Parrett
Allison Parrett
Numerade Educator
02:03

Problem 99

Indicate whether each of the following statements is correct or incorrect.
(a) Every Brønsted-Lowry acid is also a Lewis acid.
(b) Every Lewis acid is also a Bronsted-Lowry acid.
(c) Conjugate acids of weak bases produce more acidic solutions than conjugate acids of strong bases.
(d) $\mathrm{K}^{+}$ ion is acidic in water because it causes hydrating water molecules to become more acidic.
(e) The percent ionization of a weak acid in water increases as the concentration of acid decreases.

John Nicolle
John Nicolle
Numerade Educator
View

Problem 100

A solution is made by adding $1.000 \mathrm{~g} \mathrm{Ca}(\mathrm{OH})_{2}(s), 100.0 \mathrm{~mL}$
of $0.10 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4}$, and enough water to make a final volume of $350.0 \mathrm{~mL}$. Assuming that all of the solid dissolves, what is the $\mathrm{pH}$ of the final solution?

Gina Sporleder
Gina Sporleder
Numerade Educator
04:25

Problem 101

The odor of fish is due primarily to amines, especially methylamine $\left(\mathrm{CH}_{3} \mathrm{NH}_{2}\right)$. Fish is often served with a wedge of lemon, which contains citric acid. The amine and the acid react forming a product with no odor, thereby making the less-than-fresh fish more appetizing. Using data from Appendix $D$, calculate the equilibrium constant for the reaction of citric acid with methylamine, if only the first proton of the citric acid $\left(K_{a 1}\right)$ is important in the neutralization reaction.

Aadit Sharma
Aadit Sharma
Numerade Educator
03:58

Problem 102

Which, if any, of the following statements are true?
(a) The stronger the base, the smaller the $\mathrm{p} K_{b}$.
(b) The stronger the base, the larger the $\mathrm{p} K_{b}$.
(c) The stronger the base, the smaller the $K_{b}$.
(d) The stronger the base, the larger the $K_{b}$.
(e) The stronger the base, the smaller the $\mathrm{p} K_{a}$ of its conjugate acid.
(f) The stronger the base, the larger the $\mathrm{p} K_{a}$ of its conjugate acid.

Sima Sarker
Sima Sarker
Numerade Educator
02:57

Problem 103

Predict how each molecule or ion wouldact, in the BrønstedLowry sense, in aqueous solution by writing "acid," "base," "both," or "neither" on the line provided.
(a) $\mathrm{HCO}_{3}^{-},$ the bicarbonate ion:
(b) Prozac:
(c) PABA (formerly in sunscreen):
<smiles>Nc1ccc(C(=O)O)cc1</smiles>
(d) TNT, trinitrotoluene:
<smiles>Cc1c([N+](=O)[O-])cc([N+](=O)[O-])cc1[N+](=O)[O-]</smiles>
(e) $N$ -Methylpyridinium:
<smiles>Cn1cccc1</smiles>

Arun Bana
Arun Bana
Numerade Educator
03:00

Problem 104

Calculate the pH of a solution made by adding $1.00 \mathrm{~g}$ potassium oxide $\left(\mathrm{K}_{2} \mathrm{O}\right)$ to enough water to make $2.00 \mathrm{~L}$ of solution.

Aadit Sharma
Aadit Sharma
Numerade Educator
04:08

Problem 105

Benzoic acid $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}\right)$ and aniline $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}\right)$ are both derivatives of benzene. Benzoic acid is an acid with $K_{a}=6.3 \times 10^{-5}$ and aniline is a base with $K_{a}=4.3 \times 10^{-10}$ (a) What are the conjugate base of benzoic acid and the conjugate acid of aniline? (b) Anilinium chloride $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{3} \mathrm{Cl}\right)$ is a strong electrolyte that dissociates into anilinium ions $\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{3}^{+}\right)$ and chloride ions. Which will be more acidic, a $0.10 \mathrm{M}$ solution of benzoic acid or a 0.10 $M$ solution of anilinium chloride? (c) What is the value of the equilibrium constant for the following equilibrium?

Aadit Sharma
Aadit Sharma
Numerade Educator
01:21

Problem 106

What is the pH of a solution that is $1.2 \times 10^{-8} \mathrm{M}$ in $\mathrm{KOH}$ ? Does your answer make sense? What assumption do we normally make that is not valid in this case?

Anand Jangid
Anand Jangid
Numerade Educator
03:49

Problem 107

Oxalic acid $\left(\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}\right)$ is a diprotic acid. By using data in Appendix $\mathrm{D}$ as needed, determine whether each of the following statements is true:
(a) $\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4}$ can serve as both a Bronsted-Lowry acid and a Brønsted-Lowry base. (b) $\mathrm{C}_{2} \mathrm{O}_{4}^{2-}$ is the conjugate base of $\mathrm{HC}_{2} \mathrm{O}_{4}^{-}$. (c) An aqueous solution of the strong electrolyte $\mathrm{KHC}_{2} \mathrm{O}_{4}$ will have $\mathrm{pH}<7$.

Aadit Sharma
Aadit Sharma
Numerade Educator
12:04

Problem 108

Succinic acid $\left(\mathrm{H}_{2} \mathrm{C}_{4} \mathrm{H}_{6} \mathrm{O}_{4}\right),$ which we will denote $\mathrm{H}_{2} \mathrm{Suc}$
is a biologically relevant diprotic acid with the structure shown below. At $25^{\circ} \mathrm{C}$, the acid-dissociation constants for succinic acid are $K_{a 1}=6.9 \times 10^{-5}$ and $K_{a 2}=2.5 \times 10^{-6} .$
(a) Determine the pH of a $0.32 \mathrm{M}$ solution of $\mathrm{H}_{2} \mathrm{Suc}$ at $25^{\circ} \mathrm{C}$, assuming that only the first dissociation is relevant.
(b) Determine the molar concentration of $\mathrm{Suc}^{2-}$ in the solution in part (a). (c) Is the assumption you made in part
(a) justified by the result from part (b)? (d) Will a solution of the salt NaHSuc be acidic, neutral, or basic?

Allison Parrett
Allison Parrett
Numerade Educator
09:45

Problem 109

Butyric acid is responsible for the foul smell of rancid butter. The $\mathrm{pK}_{b}$ of the butyrate ion is 9.16. (a) Calculate the $K_{a}$ for butyric acid. (b) Calculate the pH of a $0.075 \mathrm{M}$ solution of butyric acid. (c) Calculate the $\mathrm{pH}$ of a $0.075 \mathrm{M}$ solution of sodium butyrate.

Sima Sarker
Sima Sarker
Numerade Educator
06:40

Problem 110

Arrange the following $0.10 \mathrm{M}$ solutions in order of increasing acidity:
(i) $\mathrm{HCOONH}_{4}$,
(ii) $\mathrm{NH}_{4} \mathrm{Br}$,
(iii) $\mathrm{NaNO}_{3}$, (iv) $\mathrm{HCOOK},(\mathrm{v}) \mathrm{KF} .$

Shubham Kumar
Shubham Kumar
Numerade Educator
01:23

Problem 111

A $0.25 M$ solution of a salt NaA has $\mathrm{pH}=9.29 .$ What is the value of $K_{a}$ for the parent acid HA?

Aadit Sharma
Aadit Sharma
Numerade Educator
06:47

Problem 112

The following observations are made about a diprotic acid $\mathrm{H}_{2} \mathrm{~A}:$ (i) $\mathrm{A} 0.10 \mathrm{M}$ solution of $\mathrm{H}_{2} \mathrm{~A}$ has $\mathrm{pH}=3.30$. (ii) $\mathrm{A} 0.10 \mathrm{M}$
solution of the salt NaHA is acidic. Which of the following could be the value of $\mathrm{p} K_{a 2}$ for $\mathrm{H}_{2} \mathrm{~A}$ :
(i) 3.22 ,
(ii) 5.30 ,
(iii) $7.47,$ or (iv) $9.82 ?$

Allison Parrett
Allison Parrett
Numerade Educator
04:23

Problem 113

Many moderately large organic molecules containing basic nitrogen atoms are not very soluble in water as neutral molecules, but they are frequently much more soluble as their acid salts. Assuming that $\mathrm{pH}$ in the stomach is 2.5 , indicate whether each of the following compounds would be present in the stomach as the neutral base or in the protonated form: nicotine, $K_{b}=7 \times 10^{-7}$; caffeine, $K_{b}=4 \times 10^{-14} ;$ strychnine, $K_{b}=1 \times 10^{-6} ;$ quinine, $K_{b}=1.1 \times 10^{-6} .$

Aadit Sharma
Aadit Sharma
Numerade Educator
07:10

Problem 114

The amino acid glycine $\left(\mathrm{H}_{2} \mathrm{~N}-\mathrm{CH}_{2}-\mathrm{COOH}\right)$ can participate in the following equilibria in water:
$\mathrm{H}_{2} \mathrm{~N}-\mathrm{CH}_{2}-\mathrm{COOH}+\mathrm{H}_{2} \mathrm{O} \rightleftharpoons$ $$ \mathrm{H}_{2} \mathrm{~N}-\mathrm{CH}_{2}-\mathrm{COO}^{-}+\mathrm{H}_{3} \mathrm{O}^{+} \quad K_{\mathrm{a}}=4.3 \times 10^{-3} $$ $$
\begin{aligned}
\mathrm{H}_{2} \mathrm{~N}-\mathrm{CH}_{2}-\mathrm{COOH}+\mathrm{H}_{2} \mathrm{O} & \rightleftharpoons \\
&{ }^{+} \mathrm{H}_{3} \mathrm{~N}-\mathrm{CH}_{2}-\mathrm{COOH}+\mathrm{OH}^{-} \quad K_{\mathrm{b}}=6.0 \times 10^{-5}
\end{aligned}
$$
(a) Use the values of $K_{a}$ and $K_{b}$ to estimate the equilibrium constant for the intramolecular proton transfer to form a zwitterion:
$$
\mathrm{H}_{2} \mathrm{~N}-\mathrm{CH}_{2}-\mathrm{COOH} \rightleftharpoons{ }^{+} \mathrm{H}_{3} \mathrm{~N}-\mathrm{CH}_{2}-\mathrm{COO}^{-}
$$
(b) What is the pH of a 0.050 Maqueous solution of glycine?
(c) What would be the predominant form of glycine in a solution with $\mathrm{pH} 13$ ? With $\mathrm{pH}$ ?

Allison Parrett
Allison Parrett
Numerade Educator
02:27

Problem 115

The $\mathrm{p} K_{\mathrm{b}}$ of water is
(a) 1
(b) 7
(c) 14
(d) not defined
(e) none of the above

Aadit Sharma
Aadit Sharma
Numerade Educator
02:52

Problem 116

Calculate the number of $\mathrm{H}^{+}(a q)$ ions in $1.0 \mathrm{~mL}$ of pure water at $25^{\circ} \mathrm{C}$.

Allison Parrett
Allison Parrett
Numerade Educator
03:23

Problem 117

How many milliliters of concentrated hydrochloric acid solution $(36.0 \%$ HCl by mass, density $=1.18 \mathrm{~g} / \mathrm{mL}$ ) are required to produce $10.0 \mathrm{~L}$ of a solution that has a pH of $2.05 ?$

Aadit Sharma
Aadit Sharma
Numerade Educator
04:05

Problem 118

The volume of an adult's stomach ranges from about 50 $\mathrm{mL}$ when empty to $1 \mathrm{~L}$ when full. If the stomach volume is $400 \mathrm{~mL}$ and its contents have a pH of 2 , how many moles of $\mathrm{H}^{+}$ does the stomach contain? Assuming that all the $\mathrm{H}^{+}$ comes from $\mathrm{HCl}$, how many grams of sodium hydrogen carbonate will totally neutralize the stomach acid?

Susan Hallstrom
Susan Hallstrom
Numerade Educator
09:17

Problem 119

Atmospheric $\mathrm{CO}_{2}$ levels have risen by nearly $20 \%$ over the past 40 years from 320 ppm to 400 ppm. (a) Given that the average $\mathrm{pH}$ of clean, unpolluted rain today is 5.4 , determine the $\mathrm{pH}$ of unpolluted rain 40 years ago. Assume that carbonic acid $\left(\mathrm{H}_{2} \mathrm{CO}_{3}\right)$ formed by the reaction of $\mathrm{CO}_{2}$ and water is the only factor influencing $\mathrm{pH}$. $$ \mathrm{CO}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{H}_{2} \mathrm{CO}_{3}(a q) $$ (b) What volume of $\mathrm{CO}_{2}$ at $25^{\circ} \mathrm{C}$ and $101.3 \mathrm{kPa}$ is dissolved in a 20.0-L bucket of today's rainwater?

Susan Hallstrom
Susan Hallstrom
Numerade Educator
03:56

Problem 120

At $50^{\circ} \mathrm{C}$, the ion-product constant for $\mathrm{H}_{2} \mathrm{O}$ has the value $K_{w}=5.48 \times 10^{-14} \cdot(\mathbf{a})$ What is the $\mathrm{pH}$ of pure water at $50^{\circ} \mathrm{C} ?$ (b) Based on the change in $K_{w}$ with temperature, predict whether $\Delta H$ is positive, negative, or zero for the autoionization reaction of water:
$$
2 \mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{OH}^{-}(a q)
$$

Allison Parrett
Allison Parrett
Numerade Educator
04:15

Problem 121

In many reactions, the addition of $\mathrm{AlCl}_{3}$ produces the same effect as the addition of $\mathrm{H}^{+}$.
(a) Draw a Lewis structure for $\mathrm{AlCl}_{3}$ in which no atoms carry formal charges, and determine its structure using the VSEPR method.
(b) What characteristic is notable about the structure in part
(a) that helps us understand the acidic character of $\mathrm{AlCl}_{3}$ ?
(c) Predict the result of the reaction between $\mathrm{AlCl}_{3}$ and $\mathrm{NH}_{3}$ in a solvent that does not participate as a reactant.
(d) Which acid-base theory is most suitable for discussing the similarities between $\mathrm{AlCl}_{3}$ and $\mathrm{H}^{+}$ ?

Aadit Sharma
Aadit Sharma
Numerade Educator
03:10

Problem 122

What is the boiling point of a $0.10 \mathrm{M}$ solution of $\mathrm{NaHSO}_{4}$ if the solution has a density of $1.002 \mathrm{~g} / \mathrm{mL}$ ?

John Nicolle
John Nicolle
Numerade Educator
01:02

Problem 123

Use average bond enthalpies from Table 8.4 to estimate the enthalpies of the following gas-phase reactions:
$$ \begin{array}{l} \text { Reaction } 1: \mathrm{HF}(g)+\mathrm{H}_{2} \mathrm{O}(g) \rightleftharpoons \mathrm{F}^{-}(g)+\mathrm{H}_{3} \mathrm{O}^{+}(g) \\ \text { Reaction } 2: \mathrm{HCl}(g)+\mathrm{H}_{2} \mathrm{O}(g) \rightleftharpoons \mathrm{Cl}^{-}(g)+\mathrm{H}_{3} \mathrm{O}^{+ (g) \end{array} $$ Are both reactions exothermic? How do these values relate to the different strengths of hydrofluoric and hydrochloric acid?

Aadit Sharma
Aadit Sharma
Numerade Educator
06:34

Problem 124

Cocaine is a weak organic base whose molecular formula is $\mathrm{C}_{17} \mathrm{H}_{21} \mathrm{NO}_{4}$. An aqueous solution of cocaine was found to have a pH of 8.53 and an osmotic pressure of 52.7 torr at $15^{\circ} \mathrm{C}$. Calculate $K_{b}$ for cocaine.

Allison Parrett
Allison Parrett
Numerade Educator
04:31

Problem 125

The iodate ion is reduced by sulfite according to the following reaction:
$$
\mathrm{IO}_{3}^{-}(a q)+3 \mathrm{SO}_{3}^{2-}(a q) \longrightarrow \mathrm{I}^{-}(a q)+3 \mathrm{SO}_{4}^{2-}(a q)
$$
The rate of this reaction is found to be first order in $\mathrm{IO}_{3}^{-}$, first order in $\mathrm{SO}_{3}^{2-}$, and first order in $\mathrm{H}^{+}$.
(a) Write the rate law for the reaction.
(b) By what factor will the rate of the reaction change if the $\mathrm{pH}$ is lowered from 5.00 to $3.50 ?$ Does the reaction proceed more quickly or more slowly at the lower $\mathrm{pH}$ ?
(c) By using the concepts discussed in Section $14.6, \mathrm{ex}-$ plain how the reaction can be pH-dependent even though $\mathrm{H}^{+}$ does not appear in the overall reaction.

Aadit Sharma
Aadit Sharma
Numerade Educator
07:54

Problem 126

(a) Using dissociation constants from Appendix D, determine the value for the equilibrium constant for each of the following reactions.
(i) $\mathrm{HCO}_{3}^{-}(a q)+\mathrm{OH}^{-}(a q) \rightleftharpoons \mathrm{CO}_{3}^{2-}(a q)+\mathrm{H}_{2} \mathrm{O}(l)$
(ii) $\mathrm{NH}_{4}^{+}(a q)+\mathrm{CO}_{3}^{2-}(a q) \rightleftharpoons \mathrm{NH}_{3}(a q)+\mathrm{HCO}_{3}^{-}(a q)$
(b) We usually use single arrows for reactions when the forward reaction is appreciable ( $K$ much greater than 1) or when products escape from the system, so that equilibrium is never established. If we follow this convention, which of these equilibria might be written with a single arrow?

Susan Hallstrom
Susan Hallstrom
Numerade Educator