Question

Concentrated nitric acid is converted to sulphuric acid by the reaction with:
A. Sulphur dioxide
B. Concentrated sulphuric acid
C. Sulphur
D. Sulphur trioxide

Answer 1

Nitric acid is a highly corrosive mineral acid which is primarily used for nitration that means addition of nitro group. It has a chemical formula $HN{{O}_{3}}$ . Its pure form is colourless whereas the older samples have acquired a yellow colour because of the decomposition of oxides of nitrogen and water.

Complete step-by-step answer: Pure concentrated nitric acid is colourless in room temperature. Nitric acid can decompose through light therefore it is stored in brown glass bottles.
Sulphuric acid is a mineral acid which is composed of sulphur, hydrogen and oxygen having a chemical formula${{H}_{2}}S{{O}_{4}}$. It is a colourless compound which is soluble in water and is highly exothermic. It is a hygroscopic compound which absorbs water vapour from the air. It is very dangerous even at low temperatures. It is used in fertilizer manufacture.
When concentrated sulphuric acid is reacted with sulphur it results in the formation of sulphuric acid water and nitrogen dioxide.
Let us see the chemical reaction:
$S+6HN{{O}_{3}}\to {{H}_{2}}S{{O}_{4}}+2{{H}_{2}}O+6N{{O}_{2}}$
Here, nitric acid acts as an oxidising agent for sulphur where sulphur is oxidised into sulphur dioxide into the sulphur trioxide and eventually to sulphur acid.

Therefore, the correct option is (C) that is sulphur.

Note: Oxidising agent is defined as the chemical species that has the ability to oxidise other reactants and itself get reduced. Therefore, oxidising agent is said to be an electron acceptor.
Sulphur is a chemical element which has an atomic number $16$ . It is denoted with a symbol $S$ . It is a bright yellow crystalline compound at room temperature.