a)△H for the reaction of NaOH and HCl solutions will be the same as △H for reaction of KOH and HNO3 solutions because the net ionic equation is the same in each case.

b)△H for the reaction of NaOH and HCl solutions will be different from △H for the reaction between LiOH and HBr because different salt is formed.

I think a is true and b is false...

If not... I will think about it again please tell me >0<

a) Yes, the only reacting species are the ions. The other ions are called spectator ions and don not take part in the reaction.

b) Correct too, the same thing as above occurs.

If however, there was a precipitate, then there would be a difference because the formation of a precipitate involves heat release.

Sorry I am unable understand about a symbol [] but if it is sign of enthalpy then try
A is right but b I think wrong because al strong acid when react with strong base produce same heat of neutrilization its due same net ionic reaction value of heat of neutrelization is ^H= -57.1 kJ
----------------------------------------------------------pramod awasthi