Question

Consider the reaction between ammonia and water. Which reactant would be the acid and which would be the base? Explain your answer.

Answer 1

According to the Brønsted-Lowry Definition of Acids and Bases, an acid is a substance that after the reaction has a lower concentration of H+ ions, while the base accepts these H+ ions and will have a higher concentration. Let's see what is the reaction and the reaction mechanism:

`NH_(3(aq))+H_2O_((l))\rightarrow NH_(4(aq))^++OH_((aq))^-`

We see that the water donates the H+ ion, therefore the water will be the acid.

Ammonia accepts the ion H+, therefore ammonia will be the base.

Answer:

Water --->Acid

Ammonia --->Base