JEE Main 2024 Chemistry question
Match List I with List-II List-I (Name of the test): A. Borax bead test B. Charcoal cavity test C. Cobalt nitrate test D. Flame test List-II (Reaction sequence involved) [M is metal]: I. MCO₃ → MO → (Co(NO₃)₂) CoO·MO II. MCO₃ → MCl₂ → M²⁺ III. MSO₄ → (Na₂B₄O₇) M(BO₂)₂ → MBO₂ → M IV. MSO₄ → (Na₂CO₃) MCO₃ → MO → M Choose the correct answer from the option below:
Answer: (D)
Solution
Borax bead: borate; charcoal cavity: carbonate → oxide → metal; cobalt nitrate test: coloured CoO·MO; flame test: chloride → gaseous M²⁺.