The combustion of 2.900 mmol of X caused the temperature of a bomb calorimter to rise

The combustion of 2.900 mmol of X caused the temperature of a bomb calorimter to rise from 23.900 oC to 26.100 oC. Assume T = 25.000 oC, Hcomb = -3671 kJ/mol, and ng = -4 mol gas/mol X for the combustion and determine the heat capacity of the calorimeter.

okay I did .0029mols(3671 kJ/mol)(1/1000)(26.1-23.9)=.00484
but thats wrong...

constant pressure..
delta H = q ...and q= C delta T

X mol * delta H
.0029 (mol) *3671 (kJ/mol) = 10.65 (kJ)

delta H = C delta T
10.65 (kJ) = C (kJ/C) * 2.2(C)
=4.84 kJ/C