JEE Advanced 2022 — Paper 2 — CHEM-II solution

JEE Advanced2022Paper 2CHEM-II

The compound(s) which react(s) with NH $_{3}$ to give boron nitride (BN) is(are)

Solution

Boron nitride is obtained from boron sources reacting with NH $_{3}$ at high temperature:

(A) Amorphous B + NH $_{3}$ $very high T$ BN + H $_{2}$ . Correct.

(B) B $_{2}$ H $_{6}$ + excess NH $_{3}$ $high T$ (BN) $_{x}$ + H $_{2}$ (via borazine intermediate). Correct.

(D) HBF $_{4}$ + NH $_{3}$ $\to$ NH $_{4}^{+}$ BF $_{4}^{-}$ (simple acid-base salt formation, no BN). Incorrect.

$∴$ (A), (B), (C).

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