Choose the polar molecule from the following :

The bond lengths (in $\mathrm{pm})$ of $\mathrm{C}-\mathrm{C}\text{,} \mathrm{C}\equiv \mathrm{C}$ and $\mathrm{C}=\mathrm{C}$ are:

How many ions of the following have a bond order of  $2.5 ?$ 

${\mathrm{N}}_2^{-};{\mathrm{NO}}^{-};{\mathrm{C}}_2^{-};{\mathrm{N}}_2^{+};{\mathrm{C}}_2^{2-};{\mathrm{CN}}^{+}$

What will be the CORRECT order of the C-F bond distance among the following?

${\mathrm{CHF}}_3,{\mathrm{CF}}_4,{\mathrm{CH}}_3\mathrm{F}$ and ${\mathrm{CH}}_2{\mathrm{F}}_2$