Q. 3.2 moles of hydrogen iodide were heated in a sealed bulb at $444℃$ till the equilibrium state was reached. Its degree of dissociation at this temperature was found to be 22%. The number of moles of hydrogen iodide present at equilibrium are
A) 1.876
B) 2.496
C) 3.235
D) 4.126
Explanation
(b)
$2HI\ \rightleftharpoons {\ H}_{2} + \ I_{2}$
$3.2\ \ \ \ \ \ \ \ \ \ 0\ \ \ \ \ \ \ \ \ 0$ initially
$3.2 - x\ \ \ x\ \ \ \ \ \ \ \ x$ at equilibrium
$x = 22\%$ of 3.2
$= \frac{22 \times 3.2}{100}$
$= 0.704$
Hence, number of moles of HI present at equilibrium
$= 3.2 - x$
$= 3.2 - 0.704$
$= 2.496$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.