Why do we use concentration in terms of normality when all reaction can be described in terms of moles including acid base reactions in aqueous solution. So, why is this complication created by defining another term called normality exclusively for acid base reaction?

Dear Student,

Ofcourse we can consider moles when we take any acid base reaction. But a the reactions mostly occur in liquid phase. So, we need to consider volume also. To take volume into consideration, we need to use concentration in terms of normality. The water is mostly used as solvent in which the acids and bases are mixed and reaction between them is carried out. So, concentration is important and moles can not be considered here. 

Regards