Question

Out of the following the compound whose water solution has the highest `pH` is
A. `NaCI`
B. `Na_(2)CO_(3)`
C. `NH_(4)CI`
D. `NaHCO_(3)`

Answer 1

Correct Answer - B
Highest `pH` will be of the salt of `W_(A)//S_(B) (ph gt 7)`
a. NaCI (salt of `S_(A)//S_(B), pH =7`)
b. `Na_(2)CO_(3)` (salt of `W_(A)//S_(B), pH gt 7`)
c. `NH_(4)CI` (salt of `S_(A)//W_(B), pH It 7`)
d.`NaHCO_(3)` (salt of `W_(A)//S_(B), pH gt 7`)
But (b) and (d) are both salt of `W_(A)//S_(B)`, but the concentration of salt in (b) is more, so `pH` is more.
`pH=(1)/(2) (pK_(w) + pK_(a) + log C)`