What are the possible experimental errors in finding energy content of a specific food by burning it to heat water?

  • 0 votes

The two specific types of food being tested are marshmallows and cream crackers. We have to burn them, the energy they give out is used to heat water directly placed above the food in a glass beaker. The temperature change can be used to determine energy content. 

We can leave the marshmallows the same size but have to cut up the cream crackers into 4 pieces of ~same size... Why?

What are the possible experimental errors of this experiment? 

Posted Mon 1st April, 2013 @ 16:48 by Lubana

2 Answers

  • 0 votes

Do you mean like the biscuit cream crackers? In which case, I would assume it is to keep the same size roughly as the marshmallow to create a more reliable test (a giant flaming cream cracker will heat water more than a small marshmallow).

As for the experimental errors... will the heat only go to the water? Will some heat energy convect to the surroundings? Also - did you stir the water before taking a reading? Did you ensure there was the same distance between flaming food and beaker in all tests?

Answered Tue 2nd April, 2013 @ 20:26 by Didgez
  • 0 votes

Thank you! No, some heat would also be lost to the surroundings. We recorded temperature before and after but didn't stir the mixture before taking final reading. We had to weigh the cracker and record its mass at the start? And we also had to decide for ourselves when the cracker was alight and when it has stopped burning? 

Answered Mon 8th April, 2013 @ 18:07 by Lubana