ACIDS
AND BASES
(Quiz 5-1)

1. What is the value of the equilibrium constant, K_eq, for the following equilibrium? [The pK_a of HCl is –7. The concentration of water in a dilute aqueous solution is 55 M]

(A) 1.8 x 10⁵

(B) 385

(C) 1.8 x 10^-5

(D) -1.8 x 10⁵

2.Which of the following is the correct order of decreasing basicity (stronger base > weaker base)

(A) NH₃ > MeNH₂> H₂O > HF

(B) MeNH₂ > NH₃ > MeOH > CH₄

(C) NH₃ > Me₃N > H₂O > MeOH

(D) CH₃COONa > NaOH > NaOMe > NaNMe₂

3. Which of the following compounds is the strongest acid?

(A) CH₃COOH

(B) FCH₂COOH

(C) ClCH₂COOH

(D) BrCH₂COOH

4. Which of the following compounds has the highest pK_a?

(A) SiH₄

(B) HCl

(C) H₂S

(D) PH₃

5. Which of the following terms describes the reactivity of boron tribromide, BBr₃?

(A) Brønsted-Lowry acid and Lewis acid

(B) Brønsted-Lowry base and Lewis base

(C) Lewis acid and not a Brønsted-Lowry acid

(D) Lewis base and not a Brønsted-Lowry base

6. Which of the following terms describes the role of ethene in the acid-base reaction shown?

(A) Brønsted-Lowry acid

(B) Brønsted-Lowry base

(C) Lewis acid

(D) none of the above

7. Which of the following terms describes the role of ethanol in the acid-base reaction shown?

(A) Brønsted-Lowry acid

(B) Brønsted-Lowry base

(C) Lewis acid

(D) none of the above

8. Which species is the conjugate acid in the following acid-base reaction?

(A) 1

(B) 2

(C) 3

(D) 4

9. What is the value of the equilibrium constant, K_eq, for the following reaction?

(A) 10⁹

(B) 10^-9

(C) 9

(D) ¹/₉

10. Which of the following is a feature of a Lewis acid?

(A) proton donor

(B) proton acceptor

(C) electron pair donor

(D) electron pair acceptor