Hot & Cold Water
Before we begin:
You might have performed experiments of density with different materials right? Have you ever tried to compare the density of just water and water? Yes, today we will be experimenting with just two glasses of water.
- 2 Glasses
- Small cardboard paper (large enough to cover the glass opening)
- 2 different food color
- A bottle of hot water
- A bottle of cold water
How did it happen?/ Talk like a Scientist
In the activity, you tried two combinations of putting the hot and cold water one above the other.
Case I(Placing hot water above cold water) During this, although the water at the contact point is mixed up but the hot water remains at its initial position that is above the cold water.
Case II(Placing cold water above hot water) The cold water rushes down and gets mixed up with the hot water creating a mixture of lukewarm water and you cannot see the two identical colored water.
This happens because of the difference in the density. You know that when a spoon is placed over a bucket full of water, it sinks because the density of the water is less than the metal(spoon). Similarly, when you heat water, its density decreases. It is because heating the water increases its volume. As the amount of the water remains almost the same(after heating) but increased volume, the water molecules get separated a little further making it less dense. So the hot water is less dense than the cold water due to which hot water floats above cold water.
More Videos on Density:
Video 1: Sugar water density
Video 2: Oil, water and syrup