Answer:
34,690 g O₂ used.
Explanation:
Balance Equation
12B₂H + 21O₂ => 12B₂O₃ + 6H₂O
Given 14,000g B₂H moles O₂ consumed to burn 619.47 mol B₂H
=(14,000g/22.6g/mol) = 21/12 x 619.47 mole O₂ = 1084 mole O₂
= 619.47 mol B₂H used 1084 mol O₂ x 32 g/mol = 34,690 g O₂ used.