Question

The chemical name of ‘oil of vitriol’ is:
A. nitric acid
B. hydrochloric acid
C. potassium hydroxide
D. sulphuric acid

Answer 1

Hint: The answer to this question lies inside the meaning of ‘oil of vitriol’. The word ‘vitriol’ means ‘sulphates’ which resembles coloured glasses. It means that the compound definitely contains sulphate anion. The compound is prepared by roasting green vitriol in an iron retort.

Complete step by step answer:
Let us understand this question by discussing the options one-by-one:
A. Nitric acid: The chemical formula of nitric acid is $\text{HN}{\text{O}}_3$. It is a colourless, red or yellow fuming liquid. It is a strong acid which gives mono-hydrogen $\left[{\text{H}}^{+}\right]$ ion on dissociation. It contains ${\text{H}}^{+}$ as cation and nitrate or ${\text{NO}}_3^{-}$ as anion. The other names of nitric acid are aqua fortis, hydrogen nitrate and spirit of nitr.
B. Hydrochloric acid: The chemical formula of hydrochloric acid is $\text{HCl}$. It is a colourless, transparent liquid and has a pungent smell. It is a strong acid which gives mono-hydrogen $\left[{\text{H}}^{+}\right]$ ion on dissociation. It contains ${\text{H}}^{+}$ as cation and chloride or $\text{C}{\text{l}}^{-}$ as anion. The other names of hydrochloric acid are hydronium chloride, chlorhydric acid and spirits of salts.
C. Potassium hydroxide: The chemical formula of potassium hydroxide is $\text{KOH}$. It is a while coloured solid. It is an inorganic compound and a strong base which gives mono-hydroxide $\left[\text{O}{\text{H}}^{-}\right]$ ion on dissociation. It contains potassium or ${\text{K}}^{+}$ as cation and $\text{O}{\text{H}}^{-}$ as anion. The common names of potassium hydroxide are potassium hydrate, caustic potash and potash lye.
D. Sulphuric acid: The chemical formula of sulphuric acid is ${\text{H}}_2\text{S}{\text{O}}_4$. It is a clear and colourless liquid. It is a strong acid which gives dihydrogen $\left[{\text{H}}^{+}\right]$ ions on dissociation. It contains ${\text{H}}^{+}$ as cations and sulphate or ${\text{SO}}_4^{2-}$ as anion. The other names of sulphuric acid are hydrogen sulphate and oil of vitriol.

The chemical name of ‘oil of vitriol’ is sulphuric acid. The correct option is option ‘d’.

Additional Information: Uses of sulphuric acid:
(1) In iron and steel industries, sulphuric acid is used to remove rust and oxidation.
(2) Used to make phosphoric acid, which is used to make phosphate fertilizers and ammonium phosphates.

Note: The name oil of vitriol is similar to names of many compounds with the word ‘vitriol’. Do not get confused with other compounds. Like,
(1) White vitriol or $\text{ZnS}{\text{O}}_4.7{\text{H}}_2\text{O}$
(2) Red vitriol or $\text{CoS}{\text{O}}_4.7{\text{H}}_2\text{O}$
(3) Blue vitriol or $\text{CuS}{\text{O}}_4.5{\text{H}}_2\text{O}$
(4) Green vitriol or $\text{FeS}{\text{O}}_4.7{\text{H}}_2\text{O}$