Module 1   Qanuq Ilitaavut (Way of Knowing) How Fat Is a Peanut?
To find out how many calories are stored in a peanut, we will burn it and use the heat produced to warm some water. Then, knowing how many grams of water were warmed and how many degrees the temperature of the water rose, we can calculate the calories.
Materials – ring stand or other type of hanger support
– aluminum can – aluminum foil – clay
– straight pins Procedure
– peanuts
– graduated cylinder – Celsius thermometer – matches – water
1. To construct a calorimeter, use a ring stand with a hook to hold the aluminum can. Adjust the ring stand or hanger support so the bottom of the can is about 6 centimeters above the ring stand base.
2. Wrap the ring stand with aluminum foil. Leave an opening to slide clay in under can. 3. Measure 100 milliliters of water into the can. 4. Take the temperature of the water. Record your measurement on the worksheet.
5. Embed the head of a pin in a hunk of clay. Place half a shelled peanut on the point of the pin. Light the peanut with a match. As soon as it starts to burn on its own, place it under the can in the calorimeter and allow it to burn. If the peanut sputters and goes out before it looks all burned up, get a new half peanut and fresh water, and start over. When the peanut looks all burned up and goes out, take the temperature of the water again.
6. Record the temperature on your worksheet. 7. Calculate the calories using the following formula:
Amount of water used = _____milliliters = _____grams Temperature of water in degrees C before burning:__________ Temperature of water in degrees C after burning:__________ Difference in temperature:__________ Number of calories = (mass of water in grams) x (temperature change in degrees C)