Calorimetry II

Alright, but let's think this through... If metals have specific heat capacity, wouldn't my result be affected if I did the procedure in a calorimetry made of Aluminium for example?

Yes, indeed. Calorimeter made of metal have a special attention by the chemists because they know it absorbs or release way too much energy to be ignored. 

Thus, in our calculation, we need to use more information that a conventional procedure. 

The temperature change of the calorimeter needs to be accounted for. If not stated, you can assume that the temperature change of the metal is the same as that of the water.  

Lets not forget about other very special type of calorimetry: The combustion calorimetry.

It is usually done in a bomb calorimeter. With combustion, MASS ID NOT NECESSARY.