# Which of the following react with sodium in liquid ammonia?

This was a question in my question bank.

I know sodium in liquid ammonia is used to produce trans-alkenes from alkynes. But from the options, it seems all of them react with sodium in liquid ammonia. In fact, the solution in the question bank itself says:

"Solve it as a case of terminal alkynes, otherwise all alkynes react with sodium in liquid ammonia."

This doesn't make any sense to me: if all of the alkynes given react with sodium in liquid ammonia, then why the question? And what difference does it make if the alkyne is terminal?

• Note that the second compound is wrong $$\ce{CH_3CH_2C#CH_{\color{red}{3}}}$$ – Avnish Kabaj Apr 6 '18 at 6:16
• Maybe they meant $\ce{CH3CH2C}\equiv \ce{CCH3}$. – Oscar Lanzi Apr 6 '18 at 9:21