Question

In a coffee-cup calorimeter experiment, if we ignored the heat lost to the Styrofoam cup and the air, does this cause the heat gained by the total solution at the end to be too big or too small. Could you please explain.

Answer 1

A cofee cup calorimeter is used to measure the specific heat of an unknown material.

For this, the material is heated to a high temperature and is dipped in a known mass of water in a styrofoam cup.

Assuming that the heat is completely transferred to the cup, the heat gained by the solution is given by

Where c is the specific heat of water

and is the change in temperature measured using a thermometer.

Now, there is heat loss to the material of the cup and the air.

This loss is not measured.

Due to the heat loss, the change in temperature of the water is less, and the measured heat Q will be less.

So, the measurred value of heat gained by the total solution at the end will be smaller than the actual value.

But htis will be a very small value, since water ahs a very high specific heat capacity compared to any other material, and absorbs heat very easily.

Even though the measured value is small, this is not too small to cause experimental errors.