# Question 3c6f1

May 28, 2017

The concentration of $C {l}_{2}$ would increase.

#### Explanation:

I published a note on this topic ~two weeks ago... Here is the link to my answer presentation. => https://socratic.org/questions/what-is-meant-by-a-stress-on-a-reaction-at-equilibrium?source=search

Quick Answer => Adding $P C {l}_{5}$ overloads the product side of the reaction much like extra kids getting onto a balance beam (seesaw). Visualize the reaction tilting toward the product side because of the extra $P C {l}_{5}$. To reestablish the equilibrium, the reaction needs to shift away from the applied stress. This means some of the $P C {l}_{5}$ must decompose into $P C {l}_{3} \mathmr{and} C {l}_{2}$ thereby increasing the concentration of $C {l}_{2}$ (and PCl_3)# causing the balance to shift to the reactant side to establish a new equilibrium.

Go to the link mentioned above for more support on this. It is really very simple concept. Good luck.

May 28, 2017

Principle of Le Chatalier applies.....

#### Explanation:

The equilibrium position shifts so as to nullify the change you have made. The change you made was to add $P C {l}_{5}$ so to nullify this the equilibrium shifts in the direction of reagents, thereby using up some of the $P C {l}_{5}$ by decomposing it into $P C {l}_{3}$ and $C {l}_{2}$, so $C {l}_{2}$ concentration increases.