What is the effective atomic number of $$\mathrm{Zn}$$ in $$\left[\mathrm{Zn}\left(\mathrm{NH}_3\right)_4\right] \mathrm{SO}_4$$ ?

Alkyl cynides on reduction by sodium and ethanol give primary amines. This reaction is called as

Which among the following compounds has highest boiling point?

Identify the product obtained, when benzamide is treated with bromine and aqueous sodium hydroxide.