What volume of hydrogen gas, at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen?

Question

What volume of hydrogen gas, at 273 K and 1 atm pressure will be consumed in obtaining 21.6 g of elemental boron (atomic mass = 10.8) from the reduction of boron trichloride by hydrogen? (A) 89.6 L (B) 67.2 L (C) 44.8 L (D) 22.4 L

Tardigrade Admin · Accepted Answer

2BCl3 + 3H2 → 6HCl + 2B or BCl3 + (3/2) H2 → 3HCl + B 10.8 g boron requires hydrogen = (3/2) × 22.4 L 21.6 g boron will require hydrogen = (3/2) × (22.4/10.8) × 21.6 = 67.2 L

Q. What volume of hydrogen gas, at $273 K$ and $1$ atm pressure will be consumed in obtaining $21.6 g$ of elemental boron (atomic mass $= 10.8)$ from the reduction of boron trichloride by hydrogen?

89.6 L

67.2 L

44.8 L

22.4 L

$2 BC l_{3} + 3 H_{2} \to 6 H Cl + 2 B$
or $BC l_{3} + \frac{3}{2} H_{2} \to 3 H Cl + B$
$10.8 g$ boron requires hydrogen
$= \frac{3}{2} \times 22.4 L$
$21.6 g$ boron will require hydrogen
$= \frac{3}{2} \times \frac{22.4}{10.8} \times 21.6 = 67.2 L$

Q. What volume of hydrogen gas, at 273K and 1 atm pressure will be consumed in obtaining 21.6g of elemental boron (atomic mass =10.8) from the reduction of boron trichloride by hydrogen?