B ₂ H ₆ can be prepapred by reacting NaBH ₄ with BF _{3 (Boron trifluoride)} at certain conditions. Following tis the balanced reactioon satisfuying the statement.

3 NaBH ₄ (aq) + 4 BF ₃ → 3 NaBF ₄ (aq) + 2 B ₂ H ₆

Boron trifluoride is an inorganic compound which has pungent and toxic gas.