What you need:
A cola bottle with the label removed, some milk, a teaspoon What to do:
1. Open the cola bottle.
2. Pour three teaspoons of milk into the soda bottle.
3. Cap it tightly and leave undisturbed for 10-12 hours. Keep observing the bottle at intervals.
What happens?
As time passes, the cola gradually gets stripped of colour. Only a milky residue remains at the bottom of the bottle.
Why?
The milk reacts to the soda much like it reacts to lime juice. When you add lime juice to milk, the acid in it curdles the milk making it form solid globs.
Cola-flavoured soda also contains an acid called phosphoric acid that causes the milk to curdle. The phosphoric acid molecules bond with the calcium molecules in the milk. The resulting molecules are dense and hence sink to the bottom of the bottle, taking the entire colour with them.
Picture Credit : Google
