Question

The compound(s) which react(s) with $NH _3$ to give boron nitride (BN) is(are)

• A. $B$
• B. $B _2 H _6$
• C. $B _2 O _3$
• D. $HBF _4$

Answer 1

Answer: (B), (C)

(A) $2 B +2 NH _3 \rightarrow 2 BN +3 H _2$
Boron produced BN with ammonia but Boron is element not compound. So that this option not involve in answer.
(B) $3 B _2 H _6+6 NH _3 \rightarrow 3\left[ BH _2\left( NH _3\right)_2\right]^{+}\left[ BH _4^{-}\right] \xrightarrow{ T =200^{\circ} C } 2 B _3 N _3 H _6+12 H _2$ $B _3 N _3 H _6 \xrightarrow{ T >200^{\circ} C }( BN )_{ x }$
(C) $B _2 O _3(\ell)+2 NH _3 \xrightarrow{1200^{\circ} C } 2 BN _{( s )}+3 H _2 O _{( g )}$
(D) $HBF _4+ NH _3 \rightarrow NH _4\left[ BF _4\right]$