Unsaturated hydrocarbons contain multiple bonds between two $C$ atoms and show addition reactions. Give the test to distinguish ethane from ethene.

(N/A) Ethane $(C_2H_6)$ is a saturated hydrocarbon,while ethene $(C_2H_4)$ is an unsaturated hydrocarbon.
$1$. Bromine Water Test: When ethene is passed through bromine water (reddish-brown color),it reacts to form $1,2-$dibromoethane,causing the bromine water to decolorize. Ethane does not react with bromine water,so the color remains unchanged.
$2$. Baeyer's Test: Ethene reacts with alkaline $KMnO_4$ (purple color) to form ethylene glycol,causing the purple color to disappear. Ethane does not react with alkaline $KMnO_4$.