Hess's Law Manipulation for change in the Heat of Reaction Problem?

Question

I need help with this problem but i'm not sure what to do.

Here's what I am given

HClO4 + NaOH --> NaClO4 + H2O

CH3COOH + NH3 --> NH4CH3COO

CH3COOH + NaOH --> NaCH3COO + H2O

Respectively, the delta heat of reaction for each equation is:

-65.6 kJ/mol
-44.4 kJ/mol
-63.2 kJ/mol

I need to find the delta heat of reaction for:

HClO4 + NH3 --> NH4ClO4

Thanks for any input

Answer 1

Add the first two together and subtract the third. Write each equation it its ionic form, and you will see that subtracting the third equation removes everything that you don't want to appear in the equation in the question.