# QuestionAsked in: JEE Main-2003What 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 LB.67.2 LC.44.8 LD.22.4 L.

$BCl_3 + 3H \rightarrow B + 3HCl$

$BCl_3 + \frac{3}{2}H \rightarrow B + 3HCl$

Moles of boron ,$B = \frac{21.6}{10.8} = 2\ moles$

Therefore, moles of $H_2$ consumed = $\frac{3}{2}\times2= 3\ moles$

Therefore, volume of $H_2$ at NTP = $(22.4\times3)\ L = 67.2\ L$