Estimate the thermal capacitance of the system (Hint: approximate the system as 2 kg of water and 3 kg of stainless steel).
Based on your estimate of thermal capacitance, predict the temperature rise for 1 gram of Benzoic acid, which will be used as the calibration sample.
Use First Law of Thermo Q = mcv * (T2 -T1)
Q = heat of combustion
mcv = Thermal Capacitance