Burning Energy

Energy released when during the burning of a nut?

I have to design and complete a chemisrty investigation which compares the heating value of two nuts, on a per gram basis. (In other words, find which nut releases the mose energy when burnt). I have been looking for a formua or experiment which will let me do this but im having trouble finding anything. Any help would be greatly appreciated.

Public Comments

1. You could use your knowledge of specific heat capacity to solve this problem. While burning the nut, use the energy release from it to boil something (e.g. water). Measure the change in temperature. Measure the total heat energy Q=mc dT and Q is the total energy release from the nut Make sure you include possible experimental error in your report (heat loss to surroundings..etc)
2. One way to do this is to measure how much the nuts when combusted raises the temperature of a set amount of water. It takes 1 Calorie= 4.19 Joules to raise the temperature of 1 mL of water (1g) 1 degree Centigrade (˚C). So use a set amount of water (probably something relatively small) in a beaker or test tube with a thermometer (digital give faster more precise results, however a generic one will do). Record initial temperature of the water. Weigh nut A (in grams) and record. Light nut A and place it under the contain of the water. Record final temperature. Repeat using the same amount of water with the same steps, but insert nut B instead. Example for calculation per gram basis: Nut A = 7.00 grams Water = 5.00 mL Initial Temp = 20.0˚C Final Temp = 32.0˚C Change = 12.0˚C As we know 1 Calorie raises 1 mL of water 1˚C so: 12.0˚C x (1 Calorie/1˚C) = 12.0 Calories or 50.3 Joules Thats the energy required for 1 mL water, but in this case you have 5 times that, 5 mL of water. 12.0 x 5 = 60 Calories 50.3 x 5 = 252 Joules So your 7.00g Nut provided 60.0 Calories of energy or 252 Joules. In terms of per gram: 60.0 Calories/ 7.00 grams = 8.57 Calories per gram 252 Joules/ 7.00 grams = 36.0 Joules per gram *Note* I took the liberty of providing the answers in the sample calculations using significant figures. Now just do the same for Nut B and you have the two answers by gram and you can then compare the results. This method is not the most accurate, however, for a school project it should be accurate enough. Not to mention is it pretty easy to set up and clean up is easy.