1) Take about 1 gm of quick lime (CaO) in a beaker.
2) Add 10 ml of water to this.
3) Touch the beaker with your finger.
4) The beaker is hot.
5) The reason is that the calcium oxide reacts with water and releases heat energy.
6) White calcium oxide dissolves in water producing colourless solution.
7) Dip the red litmus paper in it.
8) Red litmus changes into blue colour.
9) We conclude that the solution obtained is a basic solution.