Write a test to detect the presence of double bond in a molecule.

Explanation

Presence of double bond in a molecula is detected by following two methods:
(i) `Br_(2)` in `"CC"l_(4)` test when `Br_(2)//"CC"l_(4)` is added unsaturated compound then orange colour of bromine disappears and dibromoderivative is formed. (colourless).

(ii) Bayer's test when alkaline solution of `KMnO_(4)` is added to the solution of unsaturated compound then its pink colour disappears due to the formation of dihydroxy derivative.