If the equilibrium constant for a particular chemical reaction is 1 x 10^-3, what does this tell us?

A. At equilibrium, there are more products than reactants.
B. At equilibrium, there are more reactants than products.
C. At equilibrium, there are 1 x 10^-3 moles of product.
D. At the beginning of the reaction, there are more products than reactants.

How would I answer this problem. Please help me.

2 answers

Let's take a simple reaction like
A + B ==> C, then
Keq = (C)/(A)(B)
When K = 1 that tells us that the ratio of numerator to denomnator is the same so we have equal amount of products and reactants.
If K > 1 that tells us that we have more C than A and B so we have more products than reactants.
If K < 1 that tells that we have more A and B (reactants) than C (products)
So with a value of K = 1E-3 what does that tell you?
the answer is B
at equilibrium there are more reactants than products