Change in enthalpy - delta H question?

Question

A 100mL sample of 0.200 M aqueous hydrochloric acid is added to 100mL of 0.200 M aqueous ammonia in a calorimeter whose heat capacity is zero. The following reaction occurs when the two solutions are mixed. [Assume that the density of the resulting solution is that of pure water].
HCl (aq) + NH3 --> NH4Cl (aq)
The temperature increase is 2.34 Celsius. Calculate delta H per mole of HCl and NH3 reacted.

Answer 1

1. Work out 200 x 4.18 x 2.34

2. Divide by 0.02 for the molar enthalpy change.