JEE Main 2026 — Apr 2, Shift 1 — Chemistry solution

JEE Main2026Apr 2, Shift 1Chemistry

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 $K_{2} C r O_{4}$ to give yellow precipitate. When the sodium carbonate extract of the salt solution is heated with conc. $H N O_{3}$ and ammonium molybdate, it resulted a canary yellow precipitate. The cation and anion present in the salt are respectively.

A
$C a^{2 +}$ and $S O_{4}^{2 -}$
B
$B a^{2 +}$ and $P O_{4}^{3 -}$
C
$M n^{2 +}$ and $P O_{4}^{3 -}$
D
$B a^{2 +}$ and $S O_{4}^{2 -}$

Solution

Flame test: apple green flame is characteristic of $B a^{2 +}$ ( $C a^{2 +}$ gives brick red, $S r^{2 +}$ crimson red).

Group precipitate with $K_{2} C r O_{4}$ (yellow): $B a^{2 +} + C r O_{4}^{2 -} \to B a C r O_{4} ↓$ (yellow) confirms barium.

Canary yellow precipitate with conc. $H N O_{3}$ + ammonium molybdate: classic test for phosphate, forming ammonium phosphomolybdate $(N H_{4})_{3} [P (M o_{3} O_{10})_{4}]$ .

Hence the cation is $B a^{2 +}$ and the anion is $P O_{4}^{3 -}$ .

← Back to full paper

Practice more Chemistry

Concept-wise practice with instant solutions on Fundamenthol.

Start practicing →