AP Chemistry Chapter 14 Test

For the equilibrium that exists in an aqueous solution of nitrous acid (HNO₂, a weak acid), the equilibrium constant expression is:

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• 
• 
• 

Which of the following is a conjugate acid/base pair?

• HCl/OCl^–

• H₂SO₄/SO₄^2–

• NH₄⁺/NH₃

• H₃O⁺/OH^–

The hydrogen sulfate or bisulfate ion HSO₄^– can act as either an acid or a base in water solution. In which of the following equations does HSO₄^– act as an acid?

• HSO₄^– + H₂O <--> H₂SO₄ + OH^–

• HSO₄^– + H₃O⁺ <--> SO₃ + 2H₂O

• HSO₄^– + OH^– <--> H₂SO₄ + O^2–

• HSO₄^– + H₂O <--> SO₄^2– + H₃O⁺

Given the following acids and K_a values: HClO4 (1x10⁷), HOAc (1.76x10^-5) , HCN (4.93x10^-10), HF (3.53x10^-4)

What is the order of increasing base strength?

• CN^–, F^–, OAc^–, ClO₄^–

• CN^–, OAc^–, F^–, ClO₄^–

• CN^–, ClO₄^–, F^–, OAc^–

• ClO₄^–, OAc^–, CN^–, F^–

• ClO₄^–, F^–, OAc^–, CN^–

Calculate the [H⁺] in a solution that has a pH of 9.88.

• 4.1 M

• 9.9 M

• 7.6x10^-5 M

• 1.3x10^-10 M

The pH of a solution at 25°C in which [OH^–] = 3.9 x 10^–5 M is:

• 4.41

• 3.90

• 9.59

• 4.80

Solid calcium hydroxide is dissolved in water until the pH of the solution is 11.44. The hydroxide ion concentration [OH^–] of the solution is:

• 3.6 x 10^-12 M

• 5.5 x 10^-3 M

• 2.8 x 10^-3 M

• 1.4 x 10^-3 M

At 65°C, the ion-product constant of water, K_w, is 1.20 x 10^–13. The pH of pure water at 65°C is:

• 7.000

• 6.560

• 5.880

• 6.460

Which of the following indicates the most basic solution?

• [H⁺] = 1 x 10^-10 M

• pOH=6.7

• [OH^-] = 7 x 10^-5 M

• pH=4.2

• at least two of these solutions are equally basic

Calculate the pH of 0.203 M HNO₃(aq).

• 0.693

• 2.030

• -1.140

• 13.797

• 1.595