A white water-soluble salt A gives an apple-green flame. Its solution gives (i) a white precipitate with dilute H2SO4 insoluble in dilute HNO3, (ii) a yellow precipitate with K2CrO4 in acetic acid, and (iii) a curdy white precipitate with AgNO3 that dissolves in dilute ammonia. Identify A and the amount of the precipitate in (iii) obtained from 1 mol of A.

JEE Advanced levelSingle correct optionDifficulty 3 of 3qc144

A white water-soluble salt A gives an apple-green flame. Its solution gives (i) a white precipitate with dilute $H X_{2} SO X_{4}$ insoluble in dilute $HNO X_{3}$ , (ii) a yellow precipitate with $K X_{2} CrO X_{4}$ in acetic acid, and (iii) a curdy white precipitate with $AgNO X_{3}$ that dissolves in dilute ammonia. Identify A and the amount of the precipitate in (iii) obtained from 1 mol of A.

The apple-green flame, insoluble

BaSO X_{4}

and yellow

BaCrO X_{4}

in acetic acid all indicate

Ba X^{2 +}

. The curdy white precipitate soluble in ammonia is

AgCl

, so the anion is chloride. A is

BaCl X_{2}

, and 1 mol gives 2 mol of

AgCl

BaCl X_{2} + 2 AgNO X_{3} 2 AgCl + Ba (NO X_{3}) X_{2}

CaCl X_{2}

would give a brick-red flame.