Science Buddies: "Ask an Expert"

Hi, I am doing the project Burning Calories: How much energy is stored in different types of food? And I have a question concerning it. A couple days ago, I started doing the experiment and for a marshmallow the water only went up .2 degrees Celsius. The marshmallow, along with my other food items that Science Buddies sent me(I bought the kit), only will burn for a very short period of time and then the water barely increases in temperature. Any suggestions? Am I doing something wrong? Can you please get back to me as soon as possible!?
Thank you!

Hello,

This is is a perplexing problem. I would guess that the problem might be the mass of water you are using. I don't know how much water you put in the calorimeter, but a small amount is better. A burning 23-calorie marshmallow can raise 23 g of water by just one degree Celsius, so if the water is a lot more than 23 mL that might explain the small change in temperature. Other than that, I would suggest keeping the flaming foods as close to the bottom of the tin as possible while letting the flame get plenty of air. As always, repeating the experiment multiple times improves the reliability of your results and reduces the impact of errors.
I wish you luck with your experiment; have fun and if you don't mind, post again to tell us how your project goes from here!

I used 200 mL of water, so that it probably why. It said to fill the can half full, but I will use the amount you said. And yes I can post after I'm done with the experiment. Thank you!!!