Question

Match List-I with List-II :

List - ISolid salt treated with dil. H2SO4	List - IIAnion detected
(A) effervescence of colourless gas	(I) NO2−
(B) gas with smell of rotten egg	(II) CO32−
(C) gas with pungent smell	(III) S2−
(D) brown fumes	(IV) SO23−

Identify the correct answer from the options given below :

• A. A-II, B-III, C-IV, D-I
• B. A-IV, B-III, C-II, D-I
• C. A-I, B-II, C-III, D-IV
• D. A-II, B-III, C-I, D-IV

Answer 1

The Correct Option is A

This question tests your knowledge of the qualitative analysis of anions. When a solid salt is treated with dilute sulfuric acid (H$_2$SO$_4$), different anions produce characteristic gases:
A. Effervescence of colourless gas: This indicates the presence of carbonate ions (CO$_3^{2-}$). The reaction produces carbon dioxide (CO$_2$), a colorless and odorless gas. A-II
B. Gas with smell of rotten egg: This characteristic smell indicates the presence of sulfide ions (S$^{2-}$). The reaction produces hydrogen sulfide (H$_2$S), which has a strong smell of rotten eggs. B-III
C. Gas with pungent smell: This indicates the presence of sulfite ions (SO$_3^{2-}$). The reaction produces sulfur dioxide (SO$_2$), a colorless gas with a sharp, pungent smell. C-IV
D. Brown fumes: This observation indicates the presence of nitrite ions (NO$_2^-$). The reaction produces nitrogen dioxide (NO$_2$), a brown, pungent gas. D-I