Hexamine fuel tablets are used by campers, the military and relief organizations for heating camping food or military rations. It burns smokeless, has a high energy density (30.0 kJ/g), and leaves no ashes. A student set up the following experiment to determine the enthalpy of combustion for the hexamine fuel tablets. Thermometer Aluminium cover Water DE Aluminium calorimeter hexamine tablet Four trials were performed. Each of the trials followed the same experimental design, but for each trial the container was made from a different material. The four materials used were aluminium, copper, iron and tin. The following data were collected. Mass of calorimeter (g) Mass of calorimeter and water (g) Mass of hexamine tablet (g) Initial temperature of calorimeter and contents (°C) Final temperature of calorimeter and contents (°C) Calorimeter Number Material of calorimeter • aluminium copper iron Calorimeter 1 tin 25 75 0.49 21.2 87.8 Calorimeter 2 Match the above calorimeters with their possible identity from the list below. 25 75 0.49 21.2 88.3 Calorimeter 3 Calorimeter 4 25 75 0.49 21.2 89.5 25 75 0.49 21.2 84.6

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 0.346-g sample of bisphenol A (C15H1602) in a bomb calorimeter containing 1090. g of water. The temperature increases from 24.60 °C to 26.80 °C. The heat capacity of water is 4.184 J gl°C!. The molar heat of combustion is –7821 kJ per mole of bisphenol A. C15H1602(8) + 18 02(g) →15 CO2(g) + 8 H2O(1) + Energy Calculate the heat capacity of the calorimeter. heat capacity of calorimeter = J/°C

2. Fruit is impeded from ripening when it reaches high temperatures (>32°C). Farmer Joe is roo worried that Princeton's summer heat wave will affect the ripening of his ground cherries. The spherical fruit (1 cm in diameter) is surrounded by a spherical papery husk (husk = 0.3 W/m K) with an inner diameter of 2 cm and an outer diameter of 2.1 cm. The air in between the fruit and the husk is stagnant (air = 0.03 W/m K). On a calm day in July, the Princeton air (outside of the husk) is very warm, with a temperature of ~38°C and a heat transfer coefficient of hPrinceton,calm = 10 W/m².K. (a) Sketch the system, labeling all temperatures, dimensions, and proportionality constants.

What is the final temperature of a 200.00 gram sample of water (c = 4.18 J/g°C) that absorbs 5,000 Joules of heat energy after starting with a temperature of 20°C?