The average concentration of `SO_(2)` in the atmosphere over a city on a cetrain day is 10 ppm, when the average temperature is 298 K. Given that the solubility of `SO_(2)` in water at 298 K is `1.3653` mol `litre^(-1)` and the `pK_(a)` of `H_(2)SO_(3)` is `1.92`, estimate the pH of rain on that day.

Explanation

`[SO_3] = [H_2SO_3] = 1.3653 M , H_2SO_3 iff H^(+) + HSO_3^(-) , K_a = 1.2 xx 10^(-2)`
0.913