NAME DATE CLASS TEACHER SUPPORT Energy Densities of Organic Fuels Students carry out an investigation to determine how much stored energy is in fuel samples. They determine the amount of heat released from burning the fuel. Expected Outcome Fuel samples with the greatest change in water temperature contain the largest amount of stored energy Sample Data Table (Student data may vary.) Data Table Sample Initial Mass (sample and foil), g Final Mass (sample and foil), Initial Temperature of Water, °C Final Temperature of Water, °C charcoal 4.21 g 2.04 g 16.0°C 30.6 °C wood splint 0.30 g negligible 21.1 °C 30.1 °C Analyze and Interpret Data: Sample Answers 1. SEP Calculate Determine the change in temperature of the water for each fuel source by subtracting the initial water temperature from the final water temperature Charcoal 14.6°C AT = Tanan – Tintas = 30-690-16 Splint AT = Tanai – Trial = 30.10c – 21.1°C 9

NAME DATE CLASS 2. SEP Use Math Calculate the heat gained by the water when the fuels burned. Charcoal Q=m* C*AT Q = 50.0 g * 4.186 J/g°C * 14.6 °C = 3055.78Joules. Splint Q = 50.0 g * 4.186 J/g°C *_9_°C = 1983. 7 Joules 3. SEP Use Math Determine how much of the fuel burned (i.e.. the mass of the fuel converted to heat) by subtracting the final mass of the fuel/foil from the initial mass Charcoal 4.219 -2.049=2.179. Splint negligible 4. SEP Use Math Calculate the energy content per gram of fuel. This is done by dividing the heat gain of the water by the change in mass of the sample. Charcoal #2 + #3 3055.78.7 2.1792 1408.19 Splint #2 + #3 1883.73 50gr 1883.779