Draw the resonance structures of ${\mathrm{N}}_2{\mathrm{O}}_3$.

Draw the resonance structures of ${\mathrm{NO}}_2$ and ${\mathrm{N}}_2{\mathrm{O}}_4$.

Draw the resonance structures of ${\mathrm{N}}_2{\mathrm{O}}_5$. ${\mathrm{N}}_2{\mathrm{O}}_5$ is more acidic than ${\mathrm{N}}_2{\mathrm{O}}_3$. Give reason.

What happens when zinc reacts with dil. ${\mathrm{HNO}}_3$ ?

What happens when copper reacts with conc. ${\mathrm{HNO}}_3$ ?

Complete the following reaction :

$\mathrm{Cu} + {\mathrm{HNO}}_3\left(\mathrm{dilute}\right) \to$