[mariam amro]

Hello, I came across this question in a multiple choice question in my barrons SAT chemistry practice test. Can you please further explain it:

http://postimg.org/image/ub5mpkv6l/

I thought the answer was I and II because water is a product to acid base reactions.

What did I miss?

Thank you

[mjc123]

Not always. It is for, say, HCl + NaOH, but what about e.g. NH₃ + HCl?

[Respecttheyampa]

Hey Mariam,
Also to what mjc123 said, H20 is a product of acid-base reactions based on the Arrhenius theory of what defines an acid or base. That theory considers  acids as a compound that contributes a hydrogen protons (H+), and bases are compounds that contribute a hydroxide ion (OH-). Thus, this theory considers water as a product.

The Bronsted-Lowry definition really opens the idea of what is an acid or a base as simply proton donors or proton acceptors. So this may include more reaction possibilities that dont include water as acid-base reactions(defending mjc123's statement).

Hope that helped!