45 ml of 0.0325 M  HCN solution is titrated with 0.0200 M  NaOH solution.( Ka of  HCN =6.2  x  10 power - 10 )

1)  calculate volume of NaOH used in titration in order to reach equivalence point ?

 

2) What is the  pH of the solution at equivalent point ?

 

3) What is molar concentration of CN- at equivalent point ?