C3H7NH2 + H2O --> ??

[Kailyn Missaghi]

From textbook problem part b from #3 on chapter 6D:
propylamine (C3H7NH2) was in an aqueous solution where we were given the molar concentration and PH.

When forming the reaction of this aqueous solution, I did:
C3H7NH2 + H2O --> H3O+ + C3H7NH-

Why was this incorrect?

It says in the solutions manual, it is OH- + C3H7NH3+ on the products side but why can't I do it the other way?

How can I know when to do OH- versus when to do H3O+, as this affects my PH and POH numbers

[Nicole Coulter]

So this equation does in fact work the other way, there is a proton being taken from the H20 (water is acting as an acid), and moving over to C3H7NH2 to form C3H7NH3+, in the opposite direction the proton from C3H7NH3+ will drop forming C3H7NH2 and giving a proton back to H2O. We know that this is going to be acting as a base because the given pH for the problem is 11.86 which is greater than 7 and therefore considered "basic"