(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?
Chemistry Chapter 1 Notes Chemistry— the study of Matter Hypothesis— a tentative explanation for a series of observations. Theory— a model with which one is able to explain and make a further prediction about natural phenomena. Natural law— a concise statement, often in mathematical terms, that summarizes observations of certain natural phenomena. The form of reasoning...