Question

What is the total pressure (atm) in the chamber?

• A. $83.14$
• B. $831.4$
• C. $8.21$
• D. None

Answer 1

The correct option is C $8.21$

If $\alpha$ is the degree of dissociation for the above reaction, then under equilibrium we have the following reaction:

$H_2\left(g\right)+I_2\left(g\right)\rightleftharpoons 2HI\left(g\right)$

($0.5-\alpha$) ($0.5-\alpha$) $2\alpha$

Using definition of $K_c$, $49=\frac{4{\alpha }^2}{(0.5-\alpha {)}^2}$,

Hence, $\alpha =0.388$.

Hence, a total number of moles for the reaction is $1$.

Using the ideal gas law, $PV=nRT$,

$V=7litres$, $R=0.0821$ and $T=700K.$

Substituting the values, we get, $P_{total}=8.21atm$