State one observation for the following : Concentrated nitric acid is reacted with - sulphur.

Complete the following equations:

(i) S + Conc. HNO₃ ⟶

(ii) Cu + dil. HNO₃ ⟶

State one relevant observation for the reaction : Action of concentrated nitric acid on copper.

Write a balanced chemical equation for : Reaction of carbon powder and concentrated nitric acid.