Question

1. Which of the following substances is a strong acid? a. HCIO b. HF c. HNO2...

1. Which of the following substances is a strong acid?

a. HCIO

b. HF

c. HNO2

d. H3PO4

e. HNO3

2. What is the pH of a 0.050 M solution of NaOH, a strong base?

a. 12.70

b. 7.00

c. 13.95

d. 0.05

e. 1.30

3. The Ka of acetic acid is listed at 1.8x10-5 . What is the Kb of its conjugate base, acetate?

a. 1.8x109

b. 1.8x10-19

c. 5.56x10-10

d. 5.56x1018

e. 1.00x10-7

1. Which of the following substances is a strong acid?

a. HCIO -- weak acid

b. HF   -- weak acid

c. HNO2 -- weak acid

d. H3PO4  -- weak acid

e. HNO3 -- strong acid acid

Therefore option (e) is correct

2. What is the pH of a 0.050 M solution of NaOH, a strong base?

NaOH ---> Na+ + OH-

[OH-]=[NaOH] = 0.050 M

pOH = - log[OH-]

= - log 0.05

= 1.3

We know that pH + pOH = 14

pH = 14 - pOH

= 14 - 1.3

= 12.70

Therefore option (a) is correct.

3. The Ka  of acetic acid is listed at 1.8x10-5 . What is the Kb of its conjugate base, acetate?

We knon that Ka x Kb = Kw = 1.0x10-14

So Kb = Kw / Ka

= (1.0x10-14 )/ (1.8x10-5 )

= 5.56x10-10

Therfore option (c) is correct