chapter 2

Question 1

The equilibrium constant of a reaction is a measure of:

Answer 1

how much the reaction favors the products.

Question 2

If a conjugate acid-base pair had a pKa of 8, what BEST describes the pH range in which it is an effective buffer?

Answer 2

pH 7-9

Question 3

What is the pKa of water if the ion product Kw is 1 × 10−14 and the concentration of pure water is 55.5 M?

Answer 3

15.7

Question 4

The pH of a solution with a hydroxyl ion concentration of [-OH ]=1x10-8 is

Answer 4

6

pOH=8
pH+pOH=14

14-8=6

Question 5

When the pH of a solution is zero, the proton concentration is

Answer 5

1x10^0

Question 6

pka relationship to pH

Answer 6

stronger acid=lower pKa

Question 7

a) what is the pH of a mixture of 0.042M NaH2PO4 and 0.058M Na2HPO4?

Pka HPO4=6.86

b) if 1mL of 10M NaOH is added to the buffer from part a, how much would pH change?

Answer 7

7

change to 7.2
- remember the base being added increases base conc. AND decreases acid conc.