Question #3c6f1

2 Answers
May 28, 2017

Answer:

The concentration of #Cl_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 #PCl_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 #PCl_5#. To reestablish the equilibrium, the reaction needs to shift away from the applied stress. This means some of the #PCl_5# must decompose into #PCl_3 and Cl_2# thereby increasing the concentration of #Cl_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

Answer:

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 #PCl_5# so to nullify this the equilibrium shifts in the direction of reagents, thereby using up some of the #PCl_5# by decomposing it into #PCl_3# and #Cl_2#, so #Cl_2# concentration increases.