Question

Which of the following compounds liberates hydrogen gas on reacting with sodium metal?

• A. $C_6{H}_6$
• B. $C_2{H}_2$
• C. $C_2{H}_4$
• D. $C_2{H}_6$

Answer 1

Answer: (B)

Na has basic characteristics so, it reacts with acidic compounds. In the given compounds ${\text{C}}_{\text{2}}{\text{H}}_{\text{2}}$ has acidic nature because H attached with triple bonded carbon has acidic Character so, sodium reacts with acetylene to evolve ${\text{H}}_2$ gas. $\underset{CH}{\stackrel{CH}{|||}}+2Na\to \underset{\text{Sodium}\text{acetylide}}{\underset{C.Na}{\stackrel{C.Na}{|||}}}+H_2$