Question

The pH of a 0.05 M solution of potassium hydroxide, KOH, is __________.

12.7

9

1.3

5.0

Answer 1

12.7

Step-by-step explanation:

KOH, is a strong base and will dissociate completely in water to K+ and OH-.

For every mole of KOH, there will be 1 mole of OH-, so the concentration of OH- will be the same as the concentration of KOH.

[OH-] = 0.05 M.

pOH = - log [OH-] = - log (0.05) = 1.3,

the relationship between pH and pOH is given by

pH + pOH = 14

pH = 14 - pOH

pH = 14 - 1.3 = 12.7