Q. 56 g of nitrogen and 8 g of hydrogen gas are heated in a closed vessel. At equilibrium 34 g of ammonia are present. The equilibrium number of moles of nitrogen, hydrogen and ammonia are respectively
A) 1, 2, 2
B) 2, 2, 1
C) 1, 1, 2
D) 2, 1, 2
Explanation
(c)
$N_{2}\ \ \ \ \ \ \ \ \ \ + 3H_{2} \rightleftharpoons 2NH_{3}$
Initial $\frac{56}{28} = 2$ $\frac{8}{2} = 4$
At $(2 - x)$ (4-3$x)$ $2x = \frac{34}{17} = 2$ moles
equilibrium mole mole
Hence, $x = 1$ mole
Hence, number of moles of $N_{2}$ at equilibrium
=2-1=1 mole
Number of moles of $H_{2}$ at equilibrium
=4-3=1 mole
Number of moles of $NH_{3}$ at equilibrium=2 moles
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.