Answer to Question #59002 in General Chemistry for Zain Hassan

Question

Jim, Henrietta, and Tim fill a pop can to the top with water.They place the can several inches above he flame of a single burning mini marshmallow. After the flame goes out, they do not notice any temperature change in water. They therefore conclude that zero Calories of energy were in marshmallow. Explain at least 2 problems with their experimental design.

Answer 1

1) Marshmallow has a very low calorific value comparatively to the can of water. Therefore the heat release during its burning is not enough to raise the water’s temperature to a significant value. The temperature must have been estimated by a sensitive thermometer.
2) In order to guarantee an appropriate heat transfer, the can must be placeв exactly above the flame. They must not allow several inches of distance.