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

Options

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

Answer

C

Explanation

For 1st solution, `pH = 6 rArr [H^(+)] = 10^(-6)M`
For 2nd solution, `pH = 3 rArr [H^(+)] = 10^(-3)M`
When equal volume of 1st & 2nd solution is mixed, then `[H^(+)] = (10^(-6) + 10^(-3))/(2) = 1.001 xx (10^(-3))/(2)`
`rArr pH = -"log"(1.001 xx 10^(-3))/(2) = 3.3`