Research question: How does different types of impurities in water affect the evaporation rate?

Hypothesis: Salt will slow down the rate of evaporation the most out of the three impurities tested.

Materials used:

Beakers

Water

Food colouring

Salt

Sugar

Measuring scale

Experimental procedure:

1. Fill three beakers with 250ml of water.

2. Add 10g of salt, sugar and food colouring respectively in the three beakers.

3. Stir and make sure everything dissolves.

4. Measure the weight of the beakers at every 5 minute interval.

5. Tabulate the results

Independent variable:

Sugar, salt and food colouring

Dependent variable:

The weight of the beakers

Constant variable:

Amount of water

Amount of impurities

Time of experiment

Temperature of surroundings

Humidity of surroundings

Surface area of solution