answers for general chemistry exam

Question 1 (2 points)

 Saved

What are the products of the acid–base reaction of sodium carbonate with acetic acid?

Question 1 options:

A) 

5 CO2(g) + 2 H2O(l) + 2 NaOH(aq)

B) 

CO(g) + H2O(l) + 2 NaCH3COO(aq)

C) 

H2CO3(aq) + H2O(l) + 2 NaOH(aq)

D) 

CO2(g) + H2O(l) + 2 NaCH3COO(aq)

Question 2 (2 points)

 Saved

Ammonia, NH3, is an example of a ________.

Question 2 options:

A) 

strong base

B) 

weak base

C) 

weak acid

D) 

strong acid

Question 3 (2 points)

 Saved

In the acid–base reaction: F–(aq) + HNO3(aq)  HF(aq) + NO3–(aq) ________.

Question 3 options:

A) 

F– is the acid and its conjugate base is NO3–(aq), and HNO3 is the base and its conjugate acid is HF

B) 

HNO3 is the acid and its conjugate base is HF, and F– is the base and its conjugate acid is NO3–(aq)

C) 

F– is the acid and its conjugate base is HF, and HNO3 is the base and its conjugate acid is NO3–(aq)

D) 

HNO3 is the acid and its conjugate base is NO3–(aq), and F– is the base and its conjugate acid is HF

Question 4 (2 points)

 Saved

The pH of a lime is 1.90. What is the [H3O+]?

Question 4 options:

A) 

1.3 × 1012 M H3O+

B) 

1.3 × 10–2 M H3O+

C) 

7.9 × 101 M H3O+

D) 

1.9 M H3O+

E) 

7.9 × 10–13 M H3O+

Question 5 (2 points)

 Saved

Correctly identify the conjugate acid-base pairs in the following equation:

HC2H3O2(l) + H2O(l)  H3O+(aq) + C2H3O2–(aq)

Question 5 options:

A) 

HC2H3O2/H2O and H2O/C2H3O2–

B) 

HC2H3O2/H2O and H3O+/C2H3O2–

C) 

HC2H3O2/ H3O+ and H2O/C2H3O2–

D) 

HC2H3O2/ C2H3O2–and H2O/ H3O+

Question 6 (2 points)

 Saved

Which pH value indicates the higher concentration of OH–?

Question 6 options:

A) 

pH = 10.2

B) 

pH = 11.4

C) 

pH = 3.7

D) 

pH = 8.8

E) 

pH = 6.9

Question 7 (2 points)

 Saved

Which species is the conjugate acid of HS–?

Question 7 options:

A) 

HSO2–

B) 

H+

C) 

S2–

D) 

H2S

Question 8 (2 points)

 Saved

What is the molarity of an HCl solution if 43.6 mL of a 0.125 M KOH solution are needed to titrate a 25.0 mL sample of the acid according to the equation below?

KOH(aq) + HCl(aq) → H2O(l) + KCl(aq)

Question 8 options:

A) 

0.0717 M HCl

B) 

0.573 M HCl

C) 

0.218 M HCl

D) 

4.58 M HCl

E) 

1.74 M HCl

Question 9 (2 points)

 Saved

The [H3O+] in a cabernet sauvignon wine is 5.9 × 10–4 M. What is the [–OH] in this wine?

Question 9 options:

A) 

5.9 × 10–18 M –OH

B) 

5.9 × 10–4 M –OH

C) 

1.0 × 10–7 M –OH

D) 

1.0 × 10–14 M –OH

E) 

1.7 × 10–11 M –OH

Question 10 (2 points)

 Saved

What is the molarity of an HNO3 solution if 24.1 mL of a 0.250 M Ba(OH)2 solution are needed to titrate a 15.0 mL sample of the acid according to the equation below?

Ba(OH)2(aq) + 2 HNO3(aq)  2 H2O(l) + Ba(NO3)2(aq)

Question 10 options:

A) 

0.402 M HNO3

B) 

0.803 M HNO3

C) 

0.311 M HNO3

D) 

0.156 M HNO3

E) 

0.201 M HNO3

Question 11 (2 points)

 Saved

Which species can act as a Brønsted–Lowry acid?

Question 11 options:

A) 

LiOH

B) 

Br2

C) 

CO32–

D) 

HCl

Question 12 (2 points)

 Saved

A Brønsted-Lowry acid is ________.

Question 12 options:

A) 

a compound that contains a hydrogen atom and dissolves in water to form a hydrogen ion, H+

B) 

a compound that contains hydroxide and dissolves in water to form OH–

C) 

a compound that is a proton donor

D) 

a compound that is a proton acceptor

Question 13 (2 points)

 Saved

Which acid is the strongest?

Question 13 options:

A) 

Hydrofluoric acid HF (Ka = 7.2 × 10–4)

B) 

Hydrogen sulfate ion HSO4– (Ka = 1.2 × 10–2)

C) 

Hydrocyanic acid HCN (Ka = 4.9 × 10–10)

D) 

Ammonium ion NH4+ (Ka = 5.6 × 10–10)

Question 14 (2 points)

 Saved

An Arrhenius acid is ________.

Question 14 options:

A) 

a compound that is a proton acceptor

B) 

a compound that contains a hydrogen atom and dissolves in water to form a hydrogen ion, H+

C) 

a compound that contains hydroxide and dissolves in water to form OH–

D) 

a compound that is an electron donor

Question 15 (2 points)

 Saved

A sample of water from the Chesapeake Bay has [H3O+]=3.1 × 10–9 M. Which statement below accurately describes this water sample?

Question 15 options:

A) 

The water sample has a higher concentration of hydronium ions than pure water does.

B) 

The water sample doesn't contain any hydroxide ions.

C) 

The pH of the water sample is 7.5.

D) 

The water sample is a basic solution.

Question 16 (2 points)

 Saved

Which salt forms a basic solution when dissolved in water?

Question 16 options:

A) 

KCl

B) 

Na3PO4

C) 

NH4Br

D) 

LiNO3

Question 17 (2 points)

 Saved

What is the net ionic equation for the acid–base reaction of hydrobromic acid with sodium hydroxide?

Question 17 options:

A) 

Na+(aq) + –OH(aq) + H+(aq) + Br–(aq) → H2O(l) + Na+(aq) + Br–(aq)

B) 

Na+(aq) + –OH(aq) + H+(aq) + Br–(aq) → H+(aq) + –OH(aq) + Na+(aq) + Br–(aq)

C) 

NaOH(aq) + HBr(aq) → H2O(l) + NaBr(aq)

D) 

–OH(aq) + H+(aq) → H2O(l)

Question 18 (2 points)

 Saved

Which of the following is the hydronium ion?

Question 18 options:

A) 

H+

B) 

H3O+

C) 

OH–

D) 

H2O

Question 19 (2 points)

 Saved

Which solution has the highest pH?

Question 19 options:

A) 

5.1 × 10–2 M H3O+

B) 

1.0 × 10–7 M H3O+

C) 

4.3 × 10–8 M H3O+

D) 

1.0 × 10–2 M H3O+

E) 

1.9 × 10–8 M H3O+

Question 20 (2 points)

 Saved

Which solution containing an equal number of moles of each of the substances is a buffer?

Question 20 options:

A) 

CH3COOH and NaCH3COO

B) 

H2CO3 and CO32–

C) 

HNO2 and HNO3

D) 

HCl and NaCl

E) 

More than one of the solutions is a buffer.

Question 21 (2 points)

 Saved

Which salt forms a solution with a pH < 7 when dissolved in water?

Question 21 options:

A) 

RbI

B) 

NaCH3COO

C) 

LiNO2

D) 

(NH4)2SO4

Question 22 (2 points)

 Saved

Which species is the conjugate base of NH3?

Question 22 options:

A) 

NH4OH

B) 

H2O

C) 

NH4+

D) 

NH2

E) 

NH2–

Question 23 (2 points)

 Saved

What is the pH of a peach with a [–OH] = 3.2 × 10–11 M?

Question 23 options:

A) 

3.51

B) 

11.32

C) 

3.2

D) 

10.49

Question 24 (2 points)

 Saved

Normal gastric juice has a pH of about 2. Assuming that normal gastric juice is primarily aqueous HCl, what is the concentration of HCl in the stomach?

Question 24 options:

A) 

1.0 × 102 M HCl

B) 

0.01 M HCl

C) 

0.14 M HCl

D) 

2 M HCl

Question 25 (2 points)

 Saved

Which species is the conjugate acid of HCO3–?

Question 25 options:

A) 

H2CO3

B) 

CO2

C) 

CO32–

D) 

H2O

No files..