Experiment: Boiling Water in a Paper Cup

Experiment: Boiling Water in a Paper Cup

Water draws heat away from a heat source through convection until it reaches its boiling point of 100 degrees Celsius. Most types of paper burn at 233 degrees Celsius. As the water heats up, it conducts heat away from the paper, preventing the paper from reaching that crucial temperature to prevent the paper from burning. Heat also escapes via the steam that is created when water boils.

Fill some water in a paper cup and heat it. It is observed that it is possible to boil water in a paper cup without burning the paper cup. This is because the heat given by the flame is quickly transferred from the paper cup to the water. As a result, the temperature of the paper does not reach the ignition temperature and hence is not burned. The heat gained by water raises its temperature and finally it starts boiling.

Materials

1.Paper cups.

2.Bunsen burner or heat plate.

3.Retort stand.

Procedure:

1.A small paper cup was selected.

2.The cup was supported by placing it in a small ring clamped to a retort stand.

3.Tap water was added carefully to the cup until it is filled to the very top but not overflowing.

4.The paper cup was heated gently. Be careful with flames and with hot water.

5.Heating was continued. The water was boiled.

6.The heat was removed and the cup and water was allowed to cool.

Discussion :

It is possible to boil water in a paper cup without burning the paper cup. Paper is a poor conductor of heat. Conduction of heat through the paper eventually increases the temperature of the water to its boiling point. The high heat capacity of the water keeps the paper from igniting. When you boil water in a paper cup, all of the heat is transferred to the water, not the cup. When the water starts to boil, the paper stays unburnt. After the water has boiled through, there should be a small black mark