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) 67.2 L (B) 44.8 L (C) 22.4 L (D) 89.6 L

Tardigrade Admin · Accepted Answer

2BCl3 + 3H2 → 2B + 6HCl or BCl3 + (3/2) H2 → B + 3HCl Now, since 10.8 gm boron requires hydrogen = (3/2) × 22.4 L at N.T.P hence 21.6 gm boron requires hydrogen (3/2) × (22.4/10.8)×21.6 = 67.2 L at N.T.P.

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 ?

$67.2 L$

$44.8 L$

$22.4 L$

$89.6 L$

$2 BC l_{3} + 3 H_{2} \to 2 B + 6 H Cl$
or $BC l_{3} + \frac{3}{2} H_{2} \to B + 3 H Cl$
Now, since $10.8 g m$ boron requires hydrogen
$= \frac{3}{2} \times 22.4 L$ at N.T.P
hence $21.6 g m$ boron requires hydrogen
$\frac{3}{2} \times \frac{22.4}{10.8} \times 21.6 = 67.2 L$ at N.T.P.

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 ?

67.2L

44.8L

22.4L

89.6L