Question

How many litres of water must be added to 1 litre of an aqueous solution of hcl with a ph of 1 to create an aq. Soln of ph=2?

Answer 1

10 litres of water should be added.

Answer 2

Question:

How many litres of water must be added to 1 litre an aqueous solution of HCl with a pH of 1 to create an aqueous solution with pH of 2 ?

Solution:

pH = 1 ⇒  [H+] = 10–1 = 0.1 M

pH = 2 ⇒ [H+] = 10–2 = 0.01 M

for dilution of HCl,

M1V1 = M2V2

0.1 × 1 = 0.01 × V2

V2 = 10 L

Volume of water added = 10 – 1 = 9 litre