Question

A bomb calorimeter, or constant volume calorimeter, is a device often used to determine the heat of combustion of fuels and the energy content of foods. Since the "bomb" itself can absorb energy, a separate experiment is needed to determine the heat capacity of the calorimeter. This is known as calibrating the calorimeter. In the laboratory a student burns a 0.337-g sample of bisphenol A (C15H16O2) in a bomb calorimeter containing 1040. g of water. The temperature increases from 25.90 °C to 28.10 °C. The heat capacity of water is 4.184 J g-1°C-1. The molar heat of combustion is −7821 kJ per mole of bisphenol A. C15H16O2(s) + 18 O2(g) 15 CO2(g) + 8 H2O(l) + Energy Calculate the heat capacity of the calorimeter. heat capacity of calorimeter = J/°C

Answer 1

Number of moles of biphenol = 0.337/(15*12 + 16*1 + 2*16) = 1.478 * 10^-3 moles

Heat energy gained by water q = m * S *dT

                                                       = 1040 * 4.184 * (28.1 - 25.9)

                                                       = 9572.99 J

Heat energy lost by biphenol = 1.478 * 10^-3 * 7821 * 10^3 J

                                                    = 11539.88 J

Remaing heat with caloire meter = 11539.88 - 9572.99

                                                           = 1966.89 J

Heat capacity of calorimeter = 1966.89 / (28.1-25.9) = 894.041 J / ⁰C