J.R. S. answered 04/21/21
Ph.D. University Professor with 10+ years Tutoring Experience
The heat absorbed by the calorimeter is the heat released by the combustion.
The heat absorbed (q) is equal to the change in temperature (∆T) times the heat capacity of the calorimeter (C). In equation form this is
q = C∆T
q = 7.854 kJ/º x 7.13º = 55.999 kJ
This is the heat from 2.200 g of C6H4O2 (molar mass 108 g/mol)
To find q from 1 mole, we convert as follows:
2.200 g x 1 mol/108 g = 0.0204 moles C6H4O2
55.999 kJ / 0.0204 mol = 2745 kJ/mol