Hydrazine is used as a rocket fuel. When 1.50 g of hydrazine, N2H4, was burned in a bomb calorimeter, temperature increased from 23.57 °C to 28.84 °C. The heat capacity of the calorimeter was 5.510 kJ/°C. Determine the enthalpy of combustion of octane.

Answer 1

q = Ccal x delta T = 5.510 kJ/c x (delta T) = ??
That gives you q kJ/1.5 g. Usually it is expressed as kJ/mol. Convert thre 1.5 g to moles.