Question

$BF_3$ reacts with $NaH$ at $450\, K$ to form $NaF$ and $X$. When $X$ reacts with $LiH$ in diethyl ether. Y is formed. What is Y?

• A. $LiBO_2$
• B. $Li_2B_4O_7$
• C. $LiBH_4$
• D. $B_2H_6\cdot LiH$

Answer 1

Answer: (C)

$LiBH_4$

Answer 2

$2 BF _{3}+6 NaH \stackrel{450\, K }{\longrightarrow} 6 NaF + B _{2} H _{6}(X)$
$\underset{\text{Diborane}}{B _{2} H _{6}}+2 LiH \stackrel{\text { Diethyl ether }}{\longrightarrow} \underset{\text{Lithium boron hydride}}{2 LiBH _{4}(Y)}$