Question

$3.2$ moles of hydrogen iodide were heated in a scaled bulb at ${444}^{o}C$ till the equilibrium was reached. The degree of dissociation of $HI$ at this temperature was found to be $22$%. The number of moles of hydrogen iodide present at equilibrium is:

• A. $1.87$
• B. $2.496$
• C. $4.00$
• D. $2.00$

Answer 1

The correct option is B $2.496$

$\begin{array}{cccccc}Reactionundergoesas:& 2HI& \rightleftharpoons & H_2& +& I_2\\ Att=0& 3.2& & 0& & 0\\ Atequilibrium& 3.2(1-a)& & 3.2a& & 3.2a\end{array}$

when $a=0.22$

No. of mole of $HI=3.2(1-0.22)=3.2\left(0.78\right)=2.496moles$

Ans is $B)2.496$