Which from following compounds is an example of primary amines?

Identify the technique used to know binding nature of nanomaterials?

Which from following compounds is obtained when phenol reacts with dilute nitric acid at low temperature?

In the equation, $\mathrm{BiO}_3^{-}+6 \mathrm{H}^{+}+x \mathrm{e}^{-} \rightarrow \mathrm{Bi}^{3+}+3 \mathrm{H}_2 \mathrm{O}$ What is the value of $x$ ?