Question

The following two equilibria exist simultaneously in a closed vessel :
$PC{I}_5\left(g\right)\rightleftharpoons PC{I}_3\left(g\right)+C{l}_2\left(g\right)$
$COC{I}_2\left(g\right)\rightleftharpoons CO\left(g\right)+C{I}_2\left(g\right)$
If some CO is added into the vessel, then after the equlibrium is attained again, concertration of ?

• A. $PC{I}_5$ will increase
• B. $PC{I}_5$ will decrease
• C. $PC{I}_5$ will remain unaffected
• D. $C{I}_2$ will increase

Answer 1

The correct option is C $PC{I}_5$ will remain unaffected

Given reactions are,

$PC{l}_5\rightleftharpoons PC{l}_3+C{l}_2$

$COC{l}_2\rightleftharpoons C{O}_{\left(g\right)}+C{l}_2$

If some $CO$ is added into the vessel, the concentration of $PC{l}_5$ will remain unaffected, because $CO$ reacts with $C{l}_2$ and forms $COC{l}_2$, not going to effect the concentration of $PC{l}_5$ .