When acetylene reacts with $HCl$ in the presence of $HgCl_2$,the product is

Ethylidene dichloride is obtained by the reaction of excess of $HCl$ with

What is the type and number of bonds between carbon atoms in calcium carbide?

Which of the following reactions does not give an alkyne?

Acetylene reacts with $HCN$ in the presence of $Ba(CN)_2$ to yield

When acetylene is passed through a solution of dilute sulfuric acid containing mercuric sulfate,the number of $\pi$ bonds in the final product obtained is.........