What is the initial pH of 50.0 mL of 0.100 M HNO2(nitrous, not nitric acid), point #1 ?

What is the initial pH of 50.0 mL of 0.100 M HNO2(nitrous, not nitric acid), point #1 ? Write the weak acid + strong base reaction you are doing in #1 using 0.100 M KOH as titrant (in theburet). what is the calculated mL of KOH needed to reach the equivalence point #3? (this is simple stoichiometry/factor label method starting from moles HNO2 in the beaker---> L of 0.1M KOH needed) What is the pH at the equivalence point #3?  For this problem, what ratio of [A-]/[HA] is needed for pH=pKa (at 1/2 equivalence point #2).