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

Options

A. `0.1 `L
B. `0.9` L
C. `2.0` L
D. `9.0` L

Answer

D

Explanation

pH = 1 `[H^(+)] = 10^(-1) = 0. 1 M `
`pH = 2 [H^(+)] = 10^(-2) = 0.01 M `
for dilusion of HCl `M_(1)V_(1)=M_(2)V_(2)`
`0.1 = 0.01 xx V_(2)`
`V_(2) = 10 L `
Volume of wateer added = `10 - 1 = 9 L `