Question 1

What mass of sodium formate (HCOONa) must be added to 350. mL of water in order to obtain a solution having a pH of 8.50? [Ka(HCOOH) = 1.77 * 10-4]

Accepted Answer

A)  0.23 g 
B)  4.3 g 
C)  35 g 
D)  12 g 
E)  130 g 
A)  0.23 g 
B)  4.3 g 
C)  35 g 
D)  12 g 
E)  130 g

Question 2

A 0.14 M HNO2 solution is 5.7% ionized. Calculate the H+ ion concentration.

Accepted Answer

A)  8.0 * 10-3 M 
B)  0.057 M 
C)  0.13 M 
D)  0.14 M 
E)  0.80 M 
A)  8.0 * 10-3 M 
B)  0.057 M 
C)  0.13 M 
D)  0.14 M 
E)  0.80 M

Question 3

Predict the direction in which the equilibrium will lie for the reaction H3PO4(aq) + HSO4-(aq) $\leftrightharpoons$ H2PO4-(aq) + H2SO4(aq).Ka1(H3PO4) = 7.5 * 10-3; Ka(H2SO4) = very large

Accepted Answer

A)  to the right 
B)  to the left 
C)  in the middle 
A)  to the right 
B)  to the left 
C)  in the middle

Question 4

If the pH of an acid rain storm is approximately 3.0, how many times greater is the [H+] in the rain than in a cup of coffee having a pH of 5.0

Accepted Answer

A)  1000 
B)  100 
C)  20 
D)  1.7 
E)  0.60 
A)  1000 
B)  100 
C)  20 
D)  1.7 
E)  0.60

Question 5

Which one of these net ionic equations represents the reaction of a strong acid with a weak base

Accepted Answer

A) H+(aq) + OH-(aq) $\rarr$ H2O(aq) 
B) H+(aq) + CH3NH2(aq) $\rarr$ CH3NH3+(aq) 
C) OH-(aq) + HCN(aq) $\rarr$ H2O(aq) + CN-(aq) 
D) HCN(aq) + CH3NH2(aq) $\rarr$ CH3NH3+ (aq)+ CN-(aq) 
A) H+(aq) + OH-(aq) $\rarr$ H2O(aq) 
B) H+(aq) + CH3NH2(aq) $\rarr$ CH3NH3+(aq) 
C) OH-(aq) + HCN(aq) $\rarr$ H2O(aq) + CN-(aq) 
D) HCN(aq) + CH3NH2(aq) $\rarr$ CH3NH3+ (aq)+ CN-(aq)

Question 6

Which one of these salts will form a basic solution upon dissolving in water

Accepted Answer

A)  NaI 
B)  NaF 
C)  NH4NO3 
D)  LiBr 
E)  Cr(NO3)3 
A)  NaI 
B)  NaF 
C)  NH4NO3 
D)  LiBr 
E)  Cr(NO3)3

Question 7

If the pH of stomach acid is 1.0, what is the hydroxide ion concentration in this solution

Accepted Answer

A)  4 * 10-13 M 
B)  3 * 10-13 M 
C)  2 * 10-13 M 
D)  1 * 10-13 M 
E)  None of the above 
A)  4 * 10-13 M 
B)  3 * 10-13 M 
C)  2 * 10-13 M 
D)  1 * 10-13 M 
E)  None of the above

Question 8

What is the pH of a 0.001 M Ca(OH)2 solution

Accepted Answer

A)  3.0 
B)  11.0 
C)  2.7 
D)  17.0 
E)  11.3 
A)  3.0 
B)  11.0 
C)  2.7 
D)  17.0 
E)  11.3

Question 9

The pH of coffee is approximately 5.0. How many times greater is the [H3O+] in coffee than in tap water having a pH of 8.0

Accepted Answer

A)  0.62 
B)  1.6 
C)  30 
D)  1,000 
E)  1.0 * 104 
A)  0.62 
B)  1.6 
C)  30 
D)  1,000 
E)  1.0 * 104

Question 10

Predict the direction in which the equilibrium will lie for the reaction H2CO3 + F- $\leftrightharpoons$ HCO3- + HF. Ka1( H2CO3) = 4.2 * 10-7; Ka(HF) = 7.1 * 10-4

Accepted Answer

A)  to the right 
B)  to the left 
C)  in the middle 
A)  to the right 
B)  to the left 
C)  in the middle

Question 11

For H3PO4, Ka1 = 7.3 * 10-3, Ka2 = 6.2 * 10-6, and Ka3 = 4.8 * 10-13. An aqueous solution of Na3PO4 therefore would be

Accepted Answer

A)  neutral. 
B)  basic. 
C)  acidic. 
A)  neutral. 
B)  basic. 
C)  acidic.

Question 12

Arrange the acids HBr, H2Se, and H3As in order of increasing acid strength.

Accepted Answer

A)  HBr 2Se 3As 
B)  HBr 3As 2Se 
C)  H2Se 3As 3As 2Se 3As 2Se 
A)  HBr 2Se 3As 
B)  HBr 3As 2Se 
C)  H2Se 3As 3As 2Se 3As 2Se

Question 13

Calculate the pH of a 0.20 M solution of the weak base pyridine. (C5H5N; Kb = 1.7 x 10-9)

Accepted Answer

A)  9.17 
B)  9.27 
C)  9.37 
D)  9.47 
E)  None of the above 
A)  9.17 
B)  9.27 
C)  9.37 
D)  9.47 
E)  None of the above

Question 14

What is the H+ ion concentration in a 4.8 * 10-2 M KOH solution

Accepted Answer

A)  4.8 * 10-2 M 
B)  1.0 * 10-7 M 
C)  4.8 * 10-11 M 
D)  4.8 * 10-12 M 
E)  2.1 * 10-13 M 
A)  4.8 * 10-2 M 
B)  1.0 * 10-7 M 
C)  4.8 * 10-11 M 
D)  4.8 * 10-12 M 
E)  2.1 * 10-13 M

Question 15

The equilibrium constant for the reaction C7H15COOH(aq) + HCOO-(aq) $\leftrightharpoons$ C7H15COO-(aq) + HCOOH(aq)
Is 7.23 * 10-2 at 25$\circ$C. If Ka for formic acid (HCOOH) is 1.77 * 10-4, what is the acid dissociation constant for C7H15COOH

Accepted Answer

A)  2.45 * 10-3 
B)  4.08 * 10-2 
C)  7.81 * 10-4 
D)  1.00 * 10-4 
E)  1.28 * 10-5 
A)  2.45 * 10-3 
B)  4.08 * 10-2 
C)  7.81 * 10-4 
D)  1.00 * 10-4 
E)  1.28 * 10-5

Question 16

A 1.5 L sample of a 0.44 M HBr solution is mixed with 2.2 L of a 0.080 M HClO4 solution. What is the pH of the mixture

Accepted Answer

A)  0.28 
B)  0.36 
C)  1.45 
D)  0.73 
E)  0.65 
A)  0.28 
B)  0.36 
C)  1.45 
D)  0.73 
E)  0.65

Question 17

Hard water deposits (calcium carbonate) have built up around your bathroom sink. Which one of these substances would be most effective in dissolving the deposits

Accepted Answer

A)  ammonia 
B)  bleach (sodium hypochlorite) 
C)  lye (sodium hydroxide) 
D)  vinegar (acetic acid) 
A)  ammonia 
B)  bleach (sodium hypochlorite) 
C)  lye (sodium hydroxide) 
D)  vinegar (acetic acid)

Question 18

The pH of a 0.14 M solution of an unknown monoprotic acid is 5.85. Calculate the Ka of the acid.

Accepted Answer

A)  1.4 x 10-6 
B)  1.4 x 10-11 
C)  1.0 x 10-5 
D)  7.1 x 10-9 
E)  2.0 x 10-7 
A)  1.4 x 10-6 
B)  1.4 x 10-11 
C)  1.0 x 10-5 
D)  7.1 x 10-9 
E)  2.0 x 10-7

Question 19

The compound CH3NH2 reacts with water to form CH3NH3+ and OH-. CH3NH2 acts as a base in this reaction.

Accepted Answer

A) True 
 B)False

Question 20

Diet cola drinks have a pH of about 3.0, while milk has a pH of about 7.0. How many times greater is the H3O+ concentration in diet cola than in milk

Accepted Answer

A)  2.3 times higher in diet cola than in milk 
B)  400 times higher in diet cola than in milk 
C)  0.43 times higher in diet cola than in milk 
D)  1,000 times higher in diet cola than in milk 
E)  10,000 times higher in diet cola than in milk 
A)  2.3 times higher in diet cola than in milk 
B)  400 times higher in diet cola than in milk 
C)  0.43 times higher in diet cola than in milk 
D)  1,000 times higher in diet cola than in milk 
E)  10,000 times higher in diet cola than in milk

Exam 15: Acids and Bases

What mass of sodium formate (HCOONa) must be added to 350. mL of water in order to obtain a solution having a pH of 8.50? [Ka(HCOOH) = 1.77 * 10-4]

A 0.14 M HNO2 solution is 5.7% ionized. Calculate the H+ ion concentration.

Predict the direction in which the equilibrium will lie for the reaction H3PO4(aq) + HSO4-(aq) ⇋\leftrightharpoons⇋ H2PO4-(aq) + H2SO4(aq).Ka1(H3PO4) = 7.5 * 10-3; Ka(H2SO4) = very large

If the pH of an acid rain storm is approximately 3.0, how many times greater is the [H+] in the rain than in a cup of coffee having a pH of 5.0

Which one of these net ionic equations represents the reaction of a strong acid with a weak base

Which one of these salts will form a basic solution upon dissolving in water

If the pH of stomach acid is 1.0, what is the hydroxide ion concentration in this solution

What is the pH of a 0.001 M Ca(OH)2 solution

The pH of coffee is approximately 5.0. How many times greater is the [H3O+] in coffee than in tap water having a pH of 8.0

Predict the direction in which the equilibrium will lie for the reaction H2CO3 + F- ⇋\leftrightharpoons⇋ HCO3- + HF. Ka1( H2CO3) = 4.2 * 10-7; Ka(HF) = 7.1 * 10-4

For H3PO4, Ka1 = 7.3 * 10-3, Ka2 = 6.2 * 10-6, and Ka3 = 4.8 * 10-13. An aqueous solution of Na3PO4 therefore would be

Arrange the acids HBr, H2Se, and H3As in order of increasing acid strength.

Calculate the pH of a 0.20 M solution of the weak base pyridine. (C5H5N; Kb = 1.7 x 10-9)

What is the H+ ion concentration in a 4.8 * 10-2 M KOH solution

The equilibrium constant for the reaction C7H15COOH(aq) + HCOO-(aq) ⇋\leftrightharpoons⇋ C7H15COO-(aq) + HCOOH(aq) Is 7.23 * 10-2 at 25 ∘\circ∘ C. If Ka for formic acid (HCOOH) is 1.77 * 10-4, what is the acid dissociation constant for C7H15COOH

A 1.5 L sample of a 0.44 M HBr solution is mixed with 2.2 L of a 0.080 M HClO4 solution. What is the pH of the mixture

Hard water deposits (calcium carbonate) have built up around your bathroom sink. Which one of these substances would be most effective in dissolving the deposits

The pH of a 0.14 M solution of an unknown monoprotic acid is 5.85. Calculate the Ka of the acid.

The compound CH3NH2 reacts with water to form CH3NH3+ and OH-. CH3NH2 acts as a base in this reaction.

Diet cola drinks have a pH of about 3.0, while milk has a pH of about 7.0. How many times greater is the H3O+ concentration in diet cola than in milk

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What mass of sodium formate (HCOONa) must be added to 350. mL of water in order to obtain a solution having a pH of 8.50? [K_a(HCOOH) = 1.77 * 10^-4]

A 0.14 M HNO₂ solution is 5.7% ionized. Calculate the H⁺ ion concentration.

Predict the direction in which the equilibrium will lie for the reaction H₃PO₄(aq) + HSO₄^-(aq) $\leftrightharpoons$ H₂PO₄^-(aq) + H₂SO₄(aq).K_a1(H₃PO₄) = 7.5 * 10^-3; K_a(H₂SO₄) = very large

If the pH of an acid rain storm is approximately 3.0, how many times greater is the [H⁺] in the rain than in a cup of coffee having a pH of 5.0

What is the pH of a 0.001 M Ca(OH)₂ solution

The pH of coffee is approximately 5.0. How many times greater is the [H₃O⁺] in coffee than in tap water having a pH of 8.0

Predict the direction in which the equilibrium will lie for the reaction H₂CO₃ + F^- $\leftrightharpoons$ HCO₃^- + HF. K_a1( H₂CO₃) = 4.2 * 10^-7; K_a(HF) = 7.1 * 10^-4

For H₃PO₄, K_a1 = 7.3 * 10^-3, K_a2 = 6.2 * 10^-6, and K_a3 = 4.8 * 10^-13. An aqueous solution of Na₃PO₄ therefore would be

Arrange the acids HBr, H₂Se, and H₃As in order of increasing acid strength.

Calculate the pH of a 0.20 M solution of the weak base pyridine. (C₅H₅N; K_b = 1.7 x 10^-9)

What is the H⁺ ion concentration in a 4.8 * 10^-2 M KOH solution

The equilibrium constant for the reaction C₇H₁₅COOH(aq) + HCOO^-(aq) $\leftrightharpoons$ C₇H₁₅COO^-(aq) + HCOOH(aq) Is 7.23 * 10^-2 at 25^$\circ$C. If K_a for formic acid (HCOOH) is 1.77 * 10^-4, what is the acid dissociation constant for C₇H₁₅COOH

A 1.5 L sample of a 0.44 M HBr solution is mixed with 2.2 L of a 0.080 M HClO₄ solution. What is the pH of the mixture

The pH of a 0.14 M solution of an unknown monoprotic acid is 5.85. Calculate the K_a of the acid.

The compound CH₃NH₂ reacts with water to form CH₃NH₃⁺ and OH^-. CH₃NH₂ acts as a base in this reaction.

Diet cola drinks have a pH of about 3.0, while milk has a pH of about 7.0. How many times greater is the H₃O⁺ concentration in diet cola than in milk