A 0.0258 M solution of the sodium salt, NaH of the weak monoprotic acid, HA has a pH of 9.65. Calculate Ka of the acid AH.

For the reaction Initially 2.5 moles of Fe(NO3)3 and 3.6 moles of Na2CO3 are taken. If 6.3 moles of Na2CO3 is obtained the % yield of given reaction is ?