Question

Is sulfuric acid a diprotic acid?

Answer 1

`"Sulfuric acid"` is a diprotic reagent.......

Explanation:

The conjugate base of sulfuric acid is bisulfate ion, `HSO_4^(-)`, which itself is a strongish Bronsted acid:

`H_2SO_4(l) + H_2O(l) rarr HSO_4^(-) + H_3O^+`

And `HSO_4^(-) + H_2O(l) rarr H_3O^+ + SO_4^(2-)`

Overall,

`H_2SO_4(aq) + 2H_2O rarr 2H_3O^+ + SO_4^(2-)`

You will have to look up the `K_a` for `HSO_4^(-)`, but we generally assume that sulfuric acid is diprotic in aqueous solution.