11.3 [ENDORSED]

[Michelle Dong 1F]

Write the equilibrium expression K for each of the following reactions:
(a)2C2H4(g) + O2(g) + 4HCl(g) --> <-- 2C2H4Cl2(g) + 2H2O(g)

How do we know whether to write the equilibrium Kp or Kc? In the answer key, K was written as the equilibrium expression for partial pressure (Kp), but how would we know to do that based on what the question is asking?

[Nicole Jacobs 1C]

In lecture, Lavelle said that we should give the K constant based on what is given to us, so if pressures are given, use Kp and if concentrations are given, use Kc.

[Alyssa Pelak 1J]

Hello!

You know to use partial pressures because the given expression is all gases.

Hope this helps!