Question

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

given the information what is the answer to #2

Answer 1

As heat gained,

for charcoal, ΔT = final temperature - initial temperature

= 30.6oC - 16.0oC

= 14.6oC

Q = m * C * ΔT

= 50.0g * 4.186 J/ g oC * 14.6oC

= 3055.78 J

for Splint, ΔT = final temperature - initial temperature

= 30.1oC - 21.1oC

= 9oC

Q = m * C * ΔT

= 50.0g * 4.186 J/ g oC * 9oC

= 1883.7J

Question 4.

energy content per gram of fuel = heat gain of water / change in mass of sample

for #2, energy content per gram of fuel =   3055.78 J / 2.17g

= 1408.19J/g

for #3, energy content per gram of fuel = 1883.7 J/ 0.30g

= 6279J/g

Hope this helps!