Question

A 1.800 g sample of octane, C8H18, was burned in a bomb calorimeter whose total heat capacity is 11.66 kJ/°C. The temperature of the calorimeter plus contents increased from 21.12°C to 29.85°C.
What is the heat of combustion per gram of octane?
What is the heat of combustion per mole of octane?

Answer 1

heat released = q = Ccal*delta T = 11.66 x (Tfinal-Tinitial) in kJ.
q/1.800 = heat/gram in kJ/gram
(q/1.800) x molar mass Octane = delta H/mol in kJ/mol

Answer 2

0.495