${\mathrm{B}}_2{\mathrm{H}}_6 + \mathrm{NaH} \to ?$

The correct statement(s) is / are

The reaction of diborane (B₂H₆) with NaH is NaBH₄(sodium borohydride). 

${\mathrm{B}}_2{\mathrm{H}}_6 + 2\mathrm{NaH} \to 2{\mathrm{NaBH}}_4$

Diborane can be cleaved either symmetrically or unsymmetrically. Symmetrical cleavage of diborane results in the formation of a covalent compound whereas unsymmetrical cleavage of diborane forms an ionic compound. Sodium borohydride is a covalent compound, hence there is a symmetrical cleavage of diborane when it reacts with NaH.