Ask a New Question
Menu

The equilibrium constant for the formation of phosphorus pentachloride is 1.9. If the partial pressure of each gas is 0.5 atm, will the reaction (as written) proceed forward or backward to reach equilibrium?

PCl3(g) + Cl2(g) PCl5(g)

A. Backward, because K is greater than Q
B. Backward, because K is less than Q
C. Forward, because K is less than Q
D. Forward, because K is greater than Q

I know that this is either B or D, but am not sure which. Can you help me please?

4 answers

Q=.5

K=1.9

K>Q

shifts right.

http://chem.libretexts.org/Core/Physical_and_Theoretical_Chemistry/Equilibria/Chemical_Equilibria/The_Reaction_Quotient/Difference_Between_K_And_Qhttp://chem.libretexts.org/Core/Physical_and_Theoretical_Chemistry/Equilibria/Chemical_Equilibria/The_Reaction_Quotient/Difference_Between_K_And_Q
the answer was B? K<Q
Hmmmm. We are on different planets.
its B. Q=0.5/0.5^2=2
K=1.9
Q>K so reverse reaction