Question

What chemical equation represents the ability of a substance to donate a proton in water?

A. NH3 + H2O <-> NH4+ + OH-

B. CH3COOH + H2O <-> CH3COO- + H3O+

C. CH4 + 2O2 --> CO2 + H2O

D. CH3COOH + NaOH <-> CH3COOH + NaCl

I think the answer has to be either A or B. It can't be D because Cl is randomly introduced and C isn't a reaction in water. Can you guys help me our please.

Answer 1

CH3COOH <<<< that H is a proton
CH3COO- <<<< that proton left.
H3O+ Oh, there it is !

Answer 2

So is the answer B?

Answer 3

Yes, the answer is B. The H from the -COOH group donates a proton to H2O to make the H2O become H3O^+ (the hydronium ion)
As Damon points out you should see that the CH3COOH on the left is missing the on on the right to become CH3COO- and the H2O on the right shows the H2O has been added to become H3O^+.