Question

How does the brønsted-Lowry theory define acids and bases?

Answer 1

They define acids as proton donors, and bases as proton acceptors

If you were to have:

HNO3 + H2O -> H3O+. + NO3-

You can see that the nitric acid (HNO3) gave a hydrogen ion which has 1 proton, 0 neutrons and 0 electrons to the water so we just say that it gave a proton.

Now let's see a base

NH3 + H2O -> NH4+ + OH-

Now, you can see that the ammonia (NH3) gained a hydrogen ion (proton) from the water to become ammonium(NH4). which means it accepted a proton

That's basically it. Feel free to ask if you have any further questions

Answer 2

Answer:

A  Brønsted-Lowry acid is a proton donor.

A Brønsted-Lowry base is a proton acceptor.

Explanation:

$\underbrace{\hbox{NH _{3} }}_{\hbox{base}} + \underbrace{\hbox{HCl}}_{\hbox{acid}} \longrightarrow \text{NH _{4}^{+} } + \text{Cl ^{-} }$

The NH₃ is a Brønsted-Lowry base because it accepts a proton to become NH₄⁺.

The HCl is a Brønsted-Lowry acid because it donates a proton to NH₃ and becomes Cl⁻ .