`10^(-6) M NaOH` is diluted by `100` times. The `pH` of diluted base is

Options

A. Between 5 and 6
B. Between 6 and 7
C. Between 10 and 11
D. Between 7 and 8

Answer

D

Explanation

`[OH^(-)]` of `10^(-6)` M NaOH = `10^(-6)`
When 100 times diluted ,
`[OH^(-)] = (10^(-6))/(10^(2)) = 10^(-8)`
As it is weak base, but proteolysis of water will also take place. So, the contribution of `OH^(-)` ions from water must also be considered .
` :. ` Total `[OH^(-)] = 10^(-8) +10^(-7)`