Ok sooooo...
As mentioned above c=4.2
ΔT is temp change which for 1. is 7
and m= mass of water which for 1. is 100
4.2 x 100 x 7
apply equation to second question too
For bond energies use stoichiometry ratios from given energies (oh **** ur gcse lol). Ok so use the big numbers behind the chemicals to multiply the given bond energies. Don't worry its not too difficult but im awful at explaining things