AS chemistry

[Mattykid]

The enthalpy change for the reaction between HCl and NaOH can be determined in the following way.
- 50cm^3 of 2.00mol/dm^-3 HCl is placed in a plastic cup, and its temperature recorded.
" " NaOH "
"
- The two solitions are mixed with stirring, and the final temperature recorded.
The following results were obtained from one such experiment:-
•initial temperature of both HCl abd NaOH = 18.0°C
•final temperature after mixing = 31.9°C
Calculate the heay evolved in this experiment.

What does heat evolved mean? It's worth 3 marks.