Density of salt water

Physics data shows the density of salt water is 1,027.81 kg/m3, and this density exceeds that of fresh water. Since the latter is 1,000 kg/m3. This difference arises due to their different compositions. Seawater always contains more impurities, and therefore the density of salt water is higher. A simple and accessible home experiment visually demonstrates the difference between these indicators: take two glasses of water, add salt to one, and leave the other plain. Then place hard-boiled eggs in both glasses. In one glass, the egg immediately sank, while in the other, it floated. It floated in the one where the density was higher. To explain the difference in density, you can conduct an experiment called rainbow water.

Rainbow water experiment:

You will need:

- paints;

- a brush;

- 4 small cups;

- clean water;

- a transparent glass;

- sugar;

- a teaspoon.

Procedure:

1. Pour water from a bottle into four small cups.

2. Leave the first cup unchanged.

3. Add half a teaspoon of sugar to the second cup.

4. Add one teaspoon of sugar to the third cup.

5. Add one and a half teaspoons of sugar to the fourth cup.

6. Stir the sugar in each cup.

7. Use the brush and paints to colour the liquids in all the cups different colours.

8. Next, using a syringe, draw water from the first cup, where no sugar was added at all, and carefully pour it into the glass.

9. Do the same with the next cup, which contained half a teaspoon of sugar, and slowly pour the contents of the syringe onto the bottom of the glass.

10. Do the same with the third cup.

11. Draw water from the last cup and slowly pour it into the glass.

During the experiment, you will see how the water in the glass does not mix and forms a rainbow. This experiment immediately showed four differently coloured liquids that did not mix in the glass. This happened due to their different densities. After all, each cup contained a different amount of sugar. This demonstrates that the more impurities water contains (in this case, sugar acts as the impurity), the higher its density. That is why the water with the highest density settled at the bottom of the glass and did not mix with the others. And so for each layer.

A child can perform this simple and colourful experiment on their own. However, adults can help carefully pour the water from the syringe into the glass to achieve a clearer distinction between the layers.

Videos on this topic are available on numerous video hosting sites.