Question
Question: When 100 ml Ca(OH)<sub>2</sub> solution of 0.01 M is diluted with water, the pH of the resulting sol...
When 100 ml Ca(OH)2 solution of 0.01 M is diluted with water, the pH of the resulting solution changes to 12. Volume of water added is –
A
10 ml
B
50 ml
C
100 ml
D
200 ml
Answer
100 ml
Explanation
Solution
Molarity of [OH−]Ca(OH)2 = 0.02 M (M1)
V1 = 100 ml
V2 = ?
M2 = 10–2 (pH = 12, pOH = 2, [OH–] = 10–2)
Ž 0.02 × 100 = V2 × 10–2
Ž V2 = 200 ml
Ž So volume of H2O added = V2 – V1 = 100 mL