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Chemistry Question 70 – JEE-MAIN 2026

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A salt with few drops of conc. HCl gives apple green colour in flame test. The group precipitate of the salt is dissolved in acetic acid and treated with K2CrO4 to give yellow precipitate. When the sodium carbonate extract of the salt solution is heated with conc. HNO3 and ammonium molybdate, it resulted a canary yellow precipitate. The cation and anion present in the salt are respectively,

The apple green flame test is a characteristic test for a specific alkaline earth metal ion.

Step 1: Identify the Cation using Flame Test and Chromate Test✦ Active

An apple green colour in the flame test is characteristic of Barium (Ba2+) ions. The subsequent test where the group precipitate is dissolved in acetic acid and treated with K2CrO4 to give a yellow precipitate (BaCrO4) further confirms the presence of Ba2+.

Step 2: Identify the Anion using Ammonium Molybdate Test○ Expand

The sodium carbonate extract is used to bring the anion into solution. Heating this extract with conc. HNO3 and ammonium molybdate to produce a canary yellow precipitate is a characteristic test for phosphate (PO43−) ions. The canary yellow precipitate is ammonium phosphomolybdate, (NH4)3[PMo12O40].

Step 3: Determine the Cation and Anion in the Salt○ Expand

Based on the tests, the cation present in the salt is Ba2+ and the anion is PO43−. Comparing this with the given options, option 2 matches these findings.

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