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

State one observation for the following:

Lead nitrate is heated strongly in a test tube.

Explain ostwald process of manufacture of nitric acid under the following points:

(i) Theory and equations

(ii) Labelled diagram

Complete the following reaction :

$\mathrm{C} + \mathrm{conc}.{\mathrm{HNO}}_3\to$

Complete the following reaction:

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

State one observation for the following:

Concentrated nitric acid is reacted with sulphur

Complete the following equation:

$\mathrm{S} + \mathrm{conc}. {\mathrm{HNO}}_3\to$

Identify the substance underlined:

The dilute acid which is an oxidising agent.

How many gm of the oxidising agent gets reduced in the reaction of $65.4 \mathrm{gm}$ of $\mathrm{Zn}$ with concentrated nitric acid?

[Atomic mass $\left[\mathrm{Zn}=65.4, \mathrm{N}=14, \mathrm{H}=1, \mathrm{O} =16 \mathrm{gm} {\mathrm{mol}}^{-1}\right]$]