Sapling #4

[Nayra Gharpetian 3F]

Problem 4 says: At a certain temperature, the given reaction has an equilibrium constant of Kp=341

PCl3(g)+Cl2(g)↽−−⇀PCl5(g)

PCl5 is placed in a sealed container at an initial pressure of 0.0220 bar. What is the total pressure at equilibrium?

Can someone explain how to solve this?

[Joyce Pang 2H]

You can solve this problem using ICE tables and quadratic formula. 1bar~= 1atm, so no conversion needed, and 0.0220 would be your initial pressure for PCL5 in the ICE table, while PCL2 nand Cl2 would be 0. Solve as you would for any ICE table and then plug in the values into your Kp expression, equal to the given Kp. Then you'd solve algebraically for x and add eeverything together for the total pressure. Hope that helps :)

[arisawaters2D]

When we are given an initial pressure for the product, does it mean a reverse reaction is taking place?

[Olivia Monroy 1A]

Yes I believe it would mean a reverse reaction is taken place if you are given an initial value for the product of some reaction. When solving this problem and setting the reactants to 0 initially that would also signal a reverse reaction is taking place as there are initially just P going to go to R.

[Peter DePaul 1E]

If you still need help this question here it is but with different numbers https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=49&t=71383&sid=33f225e754c1018d33ba14953deac85d

[Tobie Jessup 2E]

You can solve this problem using ICE tables and quadratic formula. 1bar~= 1atm, so no conversion needed, and 0.0220 would be your initial pressure for PCL5 in the ICE table, while PCL2 nand Cl2 would be 0. Solve as you would for any ICE table and then plug in the values into your Kp expression, equal to the given Kp. Then you'd solve algebraically for x and add eeverything together for the total pressure. Hope that helps :)

this made this problem much more clear thank you!