(a) When a 0.235-g sample of benzoic acid is combusted in a bomb calorimeter (Figure), the...

(a) When a 0.235-g sample of benzoic acid is combusted in a bomb calorimeter (Figure), the temperature rises 1.642 °C. When a 0.265-g sample of caffeine, C8H10O2N4, is burned, the temperature rises 1.525 °C. Using the value 26.38 kJ/g for the heat of combustion of benzoic acid, calculate the heat of combustion per mole of caffeine at constant volume.

Why is a stirrer used in calorimeters?

Figure Bomb calorimeter.

(b) Assuming that there is an uncertainty of 0.002 °C in each temperature reading and that the masses of samples are measured to 0.001 g, what is the estimated uncertainty in the value calculated for the heat of combustion per mole of caffeine?