What is the test for identification of double bond?

Bromine water test

There are two tests to detect the presence of unsaturated double bond in an organic molecule, the bromine water test and Bayer's test. In the bromine water test, when the molecule is added to bromine water, bromine is added to the carbon atoms across the double bond.

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.

the correct answer is:

a. formation of precipitation