Question

Which reagent used to test unsaturation of alkenes?

• A. conc. $H_{2}SO_{4}$
• B. Solution of $Br_{2}$ in $CCl_{4}$
• C. Ammonical $Cu_{2}Cl_{2}$
• D. Ammonical $AgNO_{3}$

Answer 1

Answer: (B)

Solution of bromine in carbon tetrachloride is used to test for unsaturation of alkene. The reddish brown colour of bromine disappears due to the formation of colourless dibromo ethane $\left(\right.C_{2}H_{4}Br_{2}\left.\right)$ .