What does Kc tell us?
Look at the conversation between two students about what Kc tells us.
[INSERT CI_04_cc]
Is student A correct about what Kc tells us?
No. Kc tells us nothing about the rate of a reaction.
If student B is correct, what would that mean about the proportion of products to reactants at equilibrium in a reaction for which Kc is big?
There will be a high proportion of products to reactants.
How does the Equilibrium Law help us understand the meaning of Kc?
If Kc is big it means that the ratio [products] / [reactants] is big so there is a high proprotion of products compared to reactants and the reaction is almost complete.