Chemical and Ionic Equilibrium 2 Question 53

53. 0.1M of HA is titrated with 0.1MNaOH, calculate the pH at end point. Given, Ka(HA)=5×106 and α«1.

(2004)

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Solution:

  1. At the end-point, [A]=0.05

Kb(A)=Kw/Ka=2×109 [OH]=KbC=2×109×0.05=105 pOH=5 and pH=9