Question

Which acid is formed when concentrated nitric acid reacts with sulphur?

Answer 1

The word acid originates from the Greek word acere which means sour. Historically acids were those substances which were sour in taste, turned litmus paper to red, and gave a deep pink colour when added to china rose. Acids when reacted with the bases produce neutral salt and water. Today we have six different theories for the detection of an acid.

Complete answer:
Initially acids were those substances which were sour in taste, turned litmus paper to red, and gave a deep pink colour when added to china rose. But with the development of the science and particularly in chemistry, today we six different theories to prove that any compound is acidic or not which are as follows:-
The Arrhenius concept, an acid is a compound which on hydrolysis gives ${H^ + }$ ion. For example $HN{O_3}$ .
The Lewis concept, an acid is a compound which accepts a pair of electrons. For example $B{F_3}$ .
The Bronsted Lowery concept, an acid is a compound which donated a proton. For example $HCl$ .
The Cady Elsey concept, an acid is a compound which on reaction with solvent gives cation.
The Lux Flood concept, an acid is a compound which accepts an oxide ion.
The Usanovich Concept, an acid is a compound which reacts with base, gives up cation and accepts electrons.
Nitric acid reacts with the Sulphur as follows:-
$6HN{O_3} + S \to \,{H_2}S{O_4} + 2{H_2}O + 6N{O_2}$
That means when nitric acid ( $HN{O_3}$ ) reacts with the sulphur ( $S$ ) produces Sulphuric acid( ${H_2}S{O_4}$ ) , nitrogen dioxide ( $N{O_2}$ ) ,and water.

Note:
Nitric acid on reaction with sulphur will produce sulphuric acid. One should handle acids carefully. Always add acid to water and not water to acid. Iff one adds water to acid, it will lead to an exothermic reaction and a high amount of energy is released whereas if we add acid to water the reaction is exothermic however the release of energy is very low.