Covalent compounds are soluble in ..............

The $X-X$ bond length is $1.00 \mathring{A}$ and $C-C$ bond length is $1.54 \mathring{A}$. If $EN$ of $X$ and $C$ are $3.0$ and $2.0$ respectively,the $C-X$ bond length is likely to be ............ $\mathring{A}$.

Which of the following has $p\pi-d\pi$ bonding?

Amongst the following,covalent bonding is found in:

Multiple covalent bonds exist in a molecule of

Which set contains only covalently bonded molecules?