State the property of sulphuric acid shown by the reaction of conc. sulphuric acid when heated with

(i) Potassium nitrate

(ii) Carbon

(iii) ethanol

(i) Sulphuric acid behaves as a non-volatile acid.

$\text{KNO}$3 + \text{H}2\text{SO}4 [\text{conc.}]\xrightarrow{\lt 200 \degree\text{C}} \text{KHSO}\text{4} + \text{HNO}_\bold{3}

(ii) Sulphuric acid behaves as an oxidizing agent

C + 2H₂SO₄ ⟶ CO₂ + 2H₂O + 2SO₂

(iii) Dehydrating property

C₂H₅OH $\xrightarrow[170\degree\text{C}]{\text{Conc. H}$2\text{SO}4} C₂H₄↑ + H₂O