Question

Question #c8734

Answer 1

`"Option B"`

Explanation:

Water undergoes autoprotolysis under standard conditions. What does this mean? It means that the water molecule undergoes the following equilibrium where an `O-H` bond is broken:

`2H_2O rightleftharpoons H_3O^(+) + HO^(-)`

This is an equilibrium reaction, which can certainly be measured, but it measures `[H_3O^+]` and `[HO^-]` from all sources.

i.e. `K_w = [H_3O^+][HO^-]=10^-14`

Now sulfurous acid contributes to the equilibrium:

`H_2SO_3(aq) + H_2O(l) rarr HSO_3^(-) + H_3O^+`

Since we know that `[H_3O^+] =1xx10^-3`, `[HO^-]=K_w/[[H_3O^+]]` `=` `10^-11*"mol"*L^-1`