pH of a solution produced when an aqueous soution of `pH =6` is mixed with an equal volume of an aqueous solution of `pH =3` is about `:`

Options

A. 3.3
B. 4.3
C. `4.0`
D. 4.5

Answer

A

Explanation

Assume 1 L of each solution
`[H_(3)O^(+)]` in solution of `pH =6` is `10^(-6)M`
`[H_(3)O^(+)]` in solution of `pH=3` is `10^(-3) M`
Total `[H_(3)O^(+)]=((10^(-3)+10^(-6))/(2))`
`=5.005xx10^(-4)`
`:. pH =4- lo g 5.005 ~~3.3`