A 25.0 mLof 0.1 M weak acid HA is titrated with 0.1 M NaOH to the equivalence point. If the pH at the equivalence point is 8.28 Calculate K_(a) for this acid

A 25.0 mLof 0.1 M weak acid HA is titrated with 0.1 M NaOH to the equi

1.	A 25.0 mLof 0.1 M weak acid HA is titrated with 0.1 M NaOH to the equivalence point. If the pH at the equivalence point is 8.28 Calculate K_(a) for this acid
Answer» `2.8 xx 10^(-4)` `1.3 xx 10^(-4)` `5.2 xx 10^(-9)` `1.9 xx 10^(-6)` Solution :At equivalence point, it is the hydrolysis of SALT of weak acid and strong base `pH = 7 + 1/(2)pKa + 1/2 "LOG" C`