Base Chemistry Example 2

Follow the full solution, then compare it with the other examples linked below.

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Ammonia (

\text{NH}_3

) is a base but does not contain

\text{OH}^-

. Using the Brønsted-Lowry definition, explain how

\text{NH}_3

acts as a base.

1
The Brønsted-Lowry definition: a base is a proton ( $\text{H}^+$ ) acceptor.
2
$\text{NH}_3 + \text{H}_2\text{O} \rightleftharpoons \text{NH}_4^+ + \text{OH}^-$ .
3
$\text{NH}_3$ accepts a proton from water, forming $\text{NH}_4^+$ and releasing $\text{OH}^-$ . This makes the solution basic.

Answer

\text{NH}_3\text{ accepts H}^+\text{ from water → Brønsted-Lowry base}

The Brønsted-Lowry definition is more general than Arrhenius because it does not require the base to directly contain hydroxide ions.

About Base

A substance that accepts $\text{H}^+$ ions (protons) or donates $\text{OH}^-$ ions when dissolved in solution, raising the pH above 7.

According to the Arrhenius definition, what makes a substance a base? Give two examples.

Identify whether NaOH is an acid or a base. Write the dissociation equation in water.

Is a solution with pH = 12 acidic, neutral, or basic?

A base is added to water. What happens to the hydrogen-ion concentration, and why?