GChem Question

[Lolita]

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Hi everyone,

I'm having trouble with this GChem problem from TopScore #1 and would appreciate if some kind soul could walk me through it:

14.250 moles of PCl5 gas is placed in a 3.0L container and comes to equilibrium at constant temp. 40% of the PCl5 decomposes according to PCl5 (g) <----> PCl3 (g) + Cl2 (g). What is the Kc =?

Thanks for your help.

 

[luder98]

Hi everyone,

I'm having trouble with this GChem problem from TopScore #1 and would appreciate if some kind soul could walk me through it:

14.250 moles of PCl5 gas is placed in a 3.0L container and comes to equilibrium at constant temp. 40% of the PCl5 decomposes according to PCl5 (g) <----> PCl3 (g) + Cl2 (g). What is the Kc =?

Thanks for your help.

What is your Kc formula? Make sure you don't forget the 3.
............PCl5 (g) <----> PCl3 (g) + Cl2 (g).
Before...14.25 mols........0.............0
React---.4*14.25-------.4*14.25--.4*14.25
Eq------8.55------------5.7-------5.7

Kc = 5.7*5.7/3/8.55 = 1.27

If I remember correctly, this one gives you a set of different raw calculations. It freaked me out!!! If this is the one, the answer is A! 😀