What is the `pH` of `0.01 M` glycine solution? For glycine, `K_(a_(1))=4.5xx10^(-3)` and `K_(a_(2))=1.7xx10^(-10)` at `298 K`

Options

A. `3.0`
B. `10.0`
C. `6.1`
D. `7.1`

Answer

D

Explanation

`K = K_(a_(1)) xx K_(a_(2)) = 4.5 xx 10^(-3) xx 1.7 xx 10^(-10)`
`= 7.65 xx 10^(-13)`
`= 76.5 xx 10^(-14)`
`[H^(+)] = sqrt(KC) = sqrt(76.5 xx 10^(-14) xx 10^(-2))`
`= sqrt(76.5 xx 10^(-16))`
`[H^(+)] = 8.7 xx 10^(-8)`
`P^(H) = -"log"_(10) [8.7 xx 10^(-8)]`
`= 8 - "log" 8.7, = 8 - 0.9395`
`P^(H) = 7.1`