[sam12103]

I am posting several questions that I am having trouble on a study guide for the final exam, that is why there will be several posts

31.  When 0.100 mole NH3 is dissolved in water to a volume of 1.00 L, 1.3% of the NH3 reacts
with water to form NH4+. What is the equilibrium constant for the reaction?
      NH3(aq) + H2O(l) ↔ NH4+(aq) + H3O+(aq)
a) 5.7 10-10    b) 1.7 10-5    c) 1.3 10-3    d) 1.3 10-2    e) 7.7 102


the answer to this one is b, can someone explain how they found this problem

Thank you very much guys for your help, I am having trouble with these questions.

[Wald_ron]

What do you think the first step is?

[AWK]

http://en.wikipedia.org/wiki/Law_of_dilution