Chapter 17 Chemistry II

Concepts Of Acids

100

According to Bronsted-Lowry, _____ is a proton donor and _____ is a proton acceptor.

acid

base

17.1.2

200

A _____ _____ ionizes completely in water. It is present entirely as ions; it is a _____ electrolyte. 

example:HCl

strong acid

strong

17.1.10

300

A ____ ____ is a substance that can accept a pair of electrons whereas a ____ ____ is a substance that can donate a pair of electrons. 

lewis acid

lewis base

17.2.53

400

A _____ _____ ionizes completely in water. It is present entirely as ions; it is a _____ electrolyte.

example: LiOH,NaOH,KOH

strong base

strong

17.1.11

500

A _____ _____ ionizes partly in water. It is present primarily as molecules and partly as ions; it is a _____ electrolyte.

weak acid

weak

17.1.10

600

The larger the value of ____, the ____ the acid.

K_a

stronger

17.2.3

700

A _____ _____ ionizes partly in water. It is present primarily as molecules and partly as ions; it is a _____ electrolyte. These are nitrogenous ____ such as NH₃.

weak base

weak

bases

17.1.11

Conjugate This!

100

HCl is a(n) _____. Its conjugate _____ is...

acid

base

Cl^-

17.1.6

200

HNO₃ is a(n) _____. Its conjugate _____ is...

acid

base

NO₃^-

17.1.6

300

SO₄^2- is a(n) _____. Its conjugate _____ is...

base

acid

HSO₄^-

17.1.6

400

H₃PO₄ is a(n) _____. Its conjugate _____ is...

acid

base

H₂PO₄^-

17.1.6

500

NH₃ is a(n) _____. Its conjugate _____ is...

base

acid

NH₄⁺

17.1.6

600

C₆H₅O₇^3- is a(n) _____. Its conjugate _____ is...

base

acid

HC₆H₅O₇^2-

17.1.6

700

H₂O is a(n) _____. Its conjugate _____ is...

acid and base

base, OH^-

acid, H₃O⁺

17.1.6

To Base Or Not To Base

100

H₂O(l)+NH₃(aq) ->^2 OH^-(aq)+NH₄⁺(aq)

acid donor

base acceptor

conj. base

conj. acid

17.1.3

200

CH₃COO^-(aq)+H₂O(l) ->^2 OH^-(aq)+CH₃COOH(aq)

base acceptor

acid donor

conj. base

conj. acid

17.1.3

300

What does the word proton refer to in the context of conjugate acids and bases?

it refers to H⁺

17.1.8

400

a. the conjugate base of H₂O...

b. the conjugate acid of O^2-...

c. the conjugate acid of HCO₃^-...

d. the conjugate base of HSO₄^-...

a. OH^-

b. OH^-

c. H₂CO₃

d. SO₄^2-

17.1.8

500

To find a conjugate base of a species, ____ a proton from the formula.

TO find the conjugate acid of a species, ____ a proton to the formula.

remove

add

17.1.8

600

Predict Products:

PO₄^3-(aq)+H₂O(l) -> ? 

PO₄^3- is a base because it accepts a proton. (HPO₄^2-) = conjugate acid

H₂O is an acid because it donates a proton. (OH^-) = conjugate base

PO₄^3-(aq)+H₂O(l) -> HPO₄^2-(aq)+OH^-(aq)

17.1.9

700

Predict Products:

H₂PO₄^-(aq)+CN^-(aq) -> ? 

H₂PO₄^- donates an electron, therefore is an acid. (HPO₄^2-) = conjugate base

CN^- accepts an electron, making it a base. (HCN) = conjugate acid

H₂PO₄^-(aq)+CN^-(aq) -> HPO₄^2-(aq)+HCN(aq)

17.1.9

Hydrolysis

100

____ ____ occurs when ions produced by the dissociation of a salt react with water to produce ____ or ____.

salt hydrolysis

hydroxide ion

hydronium ion

17.2.31

200

Consider the solution of sodium cyanide, NaCN.

NaCN(s) -> Na⁺(aq)+CN^-(aq)

A 0.1 M solution NaCN has a pH of 11.1 and is therefore fairly basic. How is this possible?

salt hydrolysis

17.2.30

300

Predict whether a 0.10-M solution of each of the following salts will be basic, acidic, or neutral:

a. KClO₄

b. (CH₃)₃NHCl

c. K₂C₂O₄

d. CH₃NH₃NO₃

e. NaHCO₃

a. neutral, neither K⁺ nor ClO₄^- hydrolyze

b. acidic, (CH₃)₃NH⁺ hydrolyzes

c. basic, C₂O₄^2- hydrolyzes

d. acidic, CH₃NH₃⁺ hydrolyzes

e. basic, HCO₃^- hydrolyzes 

17.2.38

400

Will it hydrolyze?

HNO₃

HCN

OH^-

NH₃

no

yes

no

yes

17.2.33

500

Predict whether a 0.10 M solution of KNO₂ will be basic, acidic, or neutral and why?

Ions in solution: K⁺ and NO₂^-

K⁺ is a Group 1A cation, and KOH is a strong base. NO₂^- is the conjugate base of the weak acid HNO₂.

The anion hydrolyzes, thus making the solution BASIC.

17.2.36

600

Predict whether a 0.10 M solution of each salt will be basic, acidic, or neutral and why?

a. LiI

b. NH₄NO₃

a. Ions in solution: Li⁺ and I^-

Li⁺ is a group 1A cation and LiOH is a strong base. I^- is the conjugate base of the strong acid HI. Therefore the solution is neutral because neither hydrolyze. 

b. Ions in solution: NH₄⁺ and NO₃^-

 NH₄⁺ is the conjugate acid of the weak base NH₃. NO₃^- is the conjugate base of the strong acid HNO₃. Therefore the solution is acidic because the cation will hydrolyze. 

17.2.35

700

Write the hydrolysis reactions and K expressions for:

a. (CH₃)₃NH⁺

b. C₂O₄^2-

c. CH₃NH₃⁺

d. HCO₃^-

a. (CH₃)₃NH⁺+ H₂O ->^2 (CH₃)₃N+H₃O⁺

K_a=[(CH₃)₃N][H₃O⁺]/[(CH₃)₃NH⁺]

b. C₂O₄^2-+H₂O ->^2 HC₂O₄^-+OH^-

K_a=[HC₂O₄^-][OH^-]/[C₂O₄^2-]

c. CH₃NH₃⁺+H₂O ->^2 CH₃NH₂+H₃O⁺

K_a=[CH₃NH₂][H₃O⁺]/[CH₃NH₃⁺]

d. HCO₃^-+H₂O ->^2 H₂CO₃+OH^-

K_a=[H₂CO₃][OH^-]/[HCO₃^-]

17.2.40

Take It To The pH Level

100

Calculate the pH of a 0.074 M solution of HF. Ka for HF is 

6.5*10^-4

pH=2.16

review sheet 2, question 2

200

Aniline, C₆H₅NH₂, is used in the manufacture of some perfumes. What is the pH of a 0.200 M solution of aniline at  25^oC ?

K_b= 4.2*10^-10  at  25^oC .

pH= 8.96

17.2.29

300

Nitrous acid (HNO₂) is a weak acid with a Ka of  4.5*10^-4 . Sodium nitrite (NaNO₂) is therefore a strong base. What will be the pH of a solution of 0.065 M sodium nitrite?

pH=8.08

review sheet 2, question 4

400

Calculate the pH at the titration endpoint, when 35.00 mL of 0.200 M methyl amine (CH₃NH₂) is titrated by 0.120 M hydrochloric acid. (K_b CH₃NH₂= 4.4*10^-4 )

pH = 5.85

review sheet 2, problem 6

500

Oxalic acid (H₂C₂O₄) is a diprotic acid with Ka₁= 5.9*10^-2 and Ka₂= 6.4*10^-5 .What is the pH of the solution of 0.035 M oxalic acid? (can one neglect the second ionization?) 

pH=1.61

review sheet 2, question 3

600

You are given 275 mL of a buffer which is 0.25 M in acetic acid and 0.15 M in sodium acetate. To this buffer you add 55 mL of 0.30 M sodium hydroxide. Calculate the pH of the buffer before and after the addition of the sodium hydroxide.

before: pH = 4.52

after: pH = 4.79

review sheet 2, question 5

700

What is the pH of a 0.040 M ammonia solution at  25^oC. K_b= 1.8*10^-5. 

pH=10.93

17.2.28

Ka-Boom!

100

K_b= ?/? 

___= Ka*? 

K_a= ?/? 

K_b= (Kw)/(Ka) 

K_w= Ka*Kb 

K_a= (Kw)/(Kb) 

17.2.42-43

200

____ is called the base ionization constant.

K_b

17.2.24

300

A weak monoprotic acid is 0.50% ionized in a 1.0 M solution. Calculate the ionization constant of the acid.

K_a= 2.5*10^-5 

17.2.16

400

A 0.015 M solution of a weak acid has a pH of 4.27. What is the Ka for this acid?

K_a= 1.92*10^-7 

review sheet 2, question 1

500

Determine the K_b of the acetate ion (C₂H₃O₂^-). The K_a of acetic acid (HC₂H₃O₂) is  1.8*10^-5 .

K_b= 5.6*10^-10 

17.2.44

600

Aspirin (acetylsalicylic acid, HC₉H₇O₄) is a weak acid. It ionizes in water according to the equation: HC₉H₇O₄(aq)+H₂O(l) ->^2 H₃O⁺(aq)+C₉H₇O₄^-(aq). A 0.10 M aqueous solution of aspirin has a pH of 2.27 at  25^oC . Determine the K_a of aspirin.

 3.0*10^-4 

17.2.15

700

Determine the K_a of the methyl ammonium ion (CH₃NH₃⁺)

K_b of methyl amine (CH₃NH₂) is  4.4*10^-4 .

K_a= 2.3*10^-11 

17.2.45

Strong As Is

100

HCl

hydrochloric acid 

17.1.10

200

HI

hydroiodic acid

17.1.10

300

HBr

hydrobromic acid

17.1.10

400

HNO₃

nitric acid

17.1.10

500

H₂SO₄

sulfuric acid

17.1.10

600

HClO₃

chloric acid

17.1.10

700

HClO₄

perchloric acid

17.1.10