The catalyst required for the dimerization of acetylene to form chloroprene is ....

An unknown compound $(A)$ has a molecular formula $C_4H_6$. When $(A)$ is treated with excess of $Br_2$, a new substance $(B)$ with formula $C_4H_6Br_4$ is formed. $(A)$ forms a white precipitate with ammoniacal silver nitrate solution. $(A)$ may be:

Which one of the following compounds will react with methyl magnesium iodide?

When $Mg_2C_3$ is reacted with water,a compound $X$ is formed which on heating with $Na$ followed by treatment with $C_2H_5Br$ gives another compound $Y$. Calculate the number of sigma bonds in $Y$.

The ozonolysis $(O_3, H_2O)$ of $(CH_3)_2CH-C \equiv C-CH_3$ gives:

Which of the following has the shortest $C - C$ bond length?