Question
Question: How many moles of NaOH must be removed from one litre of aqueous solution to change its pH from 12 t...
How many moles of NaOH must be removed from one litre of aqueous solution to change its pH from 12 to 11 ?
A
0.009
B
0.01
C
0.02
D
0.1
Answer
0.009
Explanation
Solution
Inital Final
pH = 12 pH = 11
[H+] = 10–12 M[H+] = 10–11 M
[OH–] = 10–2 M[OH–] = 10–3 M
Inital No. of mole of OH– = 10–2
Final No. of mole of OH– = 10–3
So no. of mole of OH– removed = [.01 – 0.001] = 0.009