An acid solution of `pH=6` is diluted `1000` times, the `pH` of the final solution is

Options

A. `6.01`
B. 9
C. `3.5`
D. `6.99`

Answer

D

Explanation

`because pH=6`
`therefore[H^(+)]=10^(-6)M`
After dilution `[H^(+)]=(10^(-6))/(1000)=10^(-9)M`
`therefore [H^(+)]`from `H_(2)O` cannot be neglected.
Total `[H^(+)]=10^(-9)+10^(-7)`
`=10^(-7)(10^(-2)+1)`
`=10^(-7)(1.01)`
`pH=-log (1.01xx10^(-7))`
`=7-0.0043=6.9957`