Question

Please explain this!
Which of the following chemical reactions is most likely to have the largest equilibrium constant K?

A. H3PO4(aq) + NH3(aq) H2PO4-(aq) + NH4+(aq)
B. HCl(aq) + H2O(l) H3O+(aq) + Cl-(aq)
C. CH3COO- (aq) + H2O(l) CH3COOH(aq) + OH-(aq)
D. CH3COOH(aq) + H2O(l) CH3COO- (aq) + H3O+(aq)

Answer 1

@aaronq

Answer 2

@mathstudent55 @sweetburger help?

Answer 3

\[K_c = \frac{ [products] }{ [reactants] }\] A larger equilibrium constant will be caused by a a large concentration of products at equilibrium.

Answer 4

I do know that part, but how can I tell from these equations when there are no concentrations given?

Answer 5

Notice that some reactions have weak acids, weak bases, and strong acids in the reactants. Remember that weak acids and weak basis will not react as strongly as a strong acid or strong base.

Answer 6

weak acids/bases dissociate less in water compared to the full dissociation of strong acids/bases.

Answer 7

Oh, wow, I completely forgot about that portion (my brain is fried). So I am looking at the reactants for strong acids/bases?

Answer 8

In this case you are.

Answer 9

Now which reactions have a strong acid or a strong base?

Answer 10

Well, HCl is a strong acid

Answer 11

H3PO4 and CH3COOH are both weak

Answer 12

And CH3COO- is a weak base.

Answer 13

Yes! So is the answer HCl(aq) + H2O(l) H3O+(aq) + Cl-(aq) ?

Answer 14

Yes, Exactly! This is because it will have the greatest amount of products at equilibrium.

Answer 15

That makes perfect sense! Thank you so much :)

Answer 16

Glad that it helped :).