What is the pH at the half-stoichiometric point (half-way to the endpoint) for the titration of 0.22 M HNO2(aq) with 0.10 M KOH(aq)?

What is the pH at the half-stoichiometric point (half-way to the endpoint) for the titration of 0.22 M HNO2(aq) with 0.10 M KOH(aq)?