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

B

Explanation

`pH=1 therefore [H^(+)]=10^(-1)=0.1M`
`pH=2 therefore [H^(+)]=10^(-2)=0.01M`
For dilution of `HCl, M_(1)V_(1)= M_(2)V_(2)`
`0.1xx1=0.01xxV_(2)`
`V_(2)=10L`
Volume of water to be added =10-1=9L