Question

How many litres of water must be added to 2 litre aqueous solution of `HCI` with a `pH` of 1 to create an aqueous solution with `pH` of 2 ?
A. `10L`
B. `0.9L`
C. `2L`
D. `18L`

Answer 1

Correct Answer - D
How many liters of water ……..
`pH = 1 implies [H^(+)]=10^(-1)=0.1M`
`pH=2 implies [H^(+)] = 10^(-2) = 0.01M`
for dilution of `HCI M_(1)V_(1) = M_(2)V_(2)`
`0.1xx2=0.01xxV_(2)`
`V_(2) = 20L`
Volume of water added `= 20 - 2 = 18` litre