Question

Which of the following reaction will give diborane as the product?

• A. $2NaB{H}_4+I_2\to$
• B. $LiAl{H}_4+B{F}_3\to$
• C. Both (A) and (B)
• D. None of these

Answer 1

The correct option is C Both (A) and (B)

In both the reactions, $B_2{H}_6$ will be formed.
In (a), Boron trifluoride reacts with $LiAl{H}_4$ in diethyl ether to form diborane.
$2NaB{H}_4+I_2\to B_2{H}_6+2NaI+H_2$

In (b),
$3LiAl{H}_4+4B{F}_3\stackrel{ether}{\to }2B_2{H}_6(\uparrow )+3LiF+3Al{F}_3$
The above reation is the laboratory method for preparation of diborane.
In both the reaction diborane gas is evolved. Hence, the correct answer is option (c).