Question

Which expression represents the equilibrium constant expression for sulphurous acid (H2SO3)?

Answer 1

1) Equilibrium reaction:


`H_2SO_3=H^++HSO_3^-`

2) Equilibrium constant


`Ka= ([H^+][HSO_3^-])/([H_2SO_3])`

The answer is the second option but it has a mistake because it is the ion HSO3 has oxidation state 1- and not 2-.