energy content in food
Energy content is an important property of food. The energy your body needs for running, talking, and thinking comes from the food you eat. Energy content is the amount of heat produced by the burning of 1 gram of a substance, and is measured in joules per gram (J/g). Usually, fat-rich foods like peanuts and cashews provide more energy than just carbohydrates like marshmallows.
You can determine the energy content by burning a portion of food and capturing the heat released to a known mass of water in a calorimeter. If you measure the initial and final temperatures, the energy released can be calculated using the equation:
Q = m × c × ΔT
where Q = heat absorbed (in J), m = mass (in g), c = specific heat capacity (4.184 J/g°C for water), and ΔT = change in temperature (in °C). Dividing the resulting energy value by grams of food burned gives the energy content (in J/g).
Pre-Lab:
1. Complete the PURPOSE below.
2. Make a HYPOTHESIS below: which of the two food samples you chose would have more energy than the other? Explain.
3. Read over the METHODS section and fill out the MATERIALS section!
Purpose:_________________________________________________________________________________
Hypothesis:______________________________________________________________________________
Materials:_______________________________________________________________________________
Methods:
1. Get a sample of food. Find and record the initial mass of the food sample.
2. Obtain about 50.0 mL of cold water in a small beaker.
3. Determine the mass of the aluminum container alone. Then, add the water into the container from the small beaker and measure the mass. Find the mass of the water by subtracting the mass of the container alone from the total mass.
4. Record the initial temperature of the water without the thermometer touching the bottom of the container.
5. Use the cooking lighter to light the food sample. Quickly place the burning food
You can determine the energy content by burning a portion of food and capturing the heat released to a known mass of water in a calorimeter. If you measure the initial and final temperatures, the energy released can be calculated using the equation:
Q = m × c × ΔT
where Q = heat absorbed (in J), m = mass (in g), c = specific heat capacity (4.184 J/g°C for water), and ΔT = change in temperature (in °C). Dividing the resulting energy value by grams of food burned gives the energy content (in J/g).
Pre-Lab:
1. Complete the PURPOSE below.
2. Make a HYPOTHESIS below: which of the two food samples you chose would have more energy than the other? Explain.
3. Read over the METHODS section and fill out the MATERIALS section!
Purpose:_________________________________________________________________________________
Hypothesis:______________________________________________________________________________
Materials:_______________________________________________________________________________
Methods:
1. Get a sample of food. Find and record the initial mass of the food sample.
2. Obtain about 50.0 mL of cold water in a small beaker.
3. Determine the mass of the aluminum container alone. Then, add the water into the container from the small beaker and measure the mass. Find the mass of the water by subtracting the mass of the container alone from the total mass.
4. Record the initial temperature of the water without the thermometer touching the bottom of the container.
5. Use the cooking lighter to light the food sample. Quickly place the burning food