Ask an Expert: help on food for calorimeter sci. fair project - Page 2
imastudent615 wrote:Yeah, cereal was definately a good idea. I tried a couple of samples that I had lying around the house, and I think I'll find some interesting results. I have a question about getting the results. I tried using the formula on this website, but it doesn't make much sense. I took one cornpuff and did the experiment with it. The water tempt. changed one degree. The mass went from .16 g to .02 . I used 6 oz of water which is around 177.4 g. According to the formula (Q=mc (T).) and according to that, ONE corn puff = 177.4 cal. which doesn't make sense. Am I doing something wrong with the formula? Does the mass play a part in it at all (I was reading another post, and it seems like the answer is no and I don't understand why not- shouldn't the mass affect the temperature change and the number of calories?)?
You have been unbelievably helpful, and any more help you could give would be greatly appreciated.
From the project webpage:
A calorie (lowercase "c") is actually defined by the heat capacity of water. One calorie is the amount of energy that will raise the temperature of a gram of water by 1°C. When we talk about food energy, we also use the word "Calorie," (note uppercase "C") but it is a different unit. It is the amount of energy needed to raise the temperature of a kilogram (= 1000 grams) of water by 1°C. So a Calorie is the same as 1000 calories. Or, to put it another way, 1 Calorie = 1 kcal. So in this project, for food Calories we will be careful always to use an uppercase "C".
So, does your number make more sense compared to the label on the package if you convert from calories to Calories?
As for the weight of the item, no, it doesn't matter for the formula above, but it probably matters for your experiment and data analysis. Depending on your hypothesis, you may want to calculate the calories per gram or the calories per cup or something like that. So, it is best to record this information (probably both mass and volume). You probably want to treat mass as a controlled variable (and record volume as well) and always burn 15 g or something like that. Does this make sense?
It seems that you will have a good outcome for your project. What our body needs doesn't depend on the food pyramid. It all depends on how we serve or give ourselves a great combination and amount of those foods.