Water Dilutes Blue Liquid

Open to everyone until Monday, October 5

To keep it, print it while it is open.

Adding water to a blue solution spreads the same blue material through a larger volume. The colour becomes paler because the dissolved material is less concentrated.

In the picture

Tilted small flask of dark blue liquid: the starting solution before more water is added.
Falling droplets: the blue liquid entering the larger flask.
Large flask of pale blue liquid: the same blue material spread through more water.
Empty small flask: all the dark blue liquid has moved into the large flask.

Examples

A spoonful of cordial mixed into a tall glass of water.
A drop of food colouring stirred into a bowl of water.

Key takeaways

Adding water increases the total volume, so the dissolved material is spread out more.
The total amount of dissolved material stays the same when only water is added.