Chapter 14

Q. 14.1

Explaining Acidity with the Arrhenius and Brønsted–Lowry Theories

Account for the acidic properties of nitrous acid (HNO_2) using the Arrhenius theory and the Brønsted–Lowry theory, and identify the conjugate base of HNO_2.


To account for the acidity of a substance, consider how it can produce H^+ ions in water (Arrhenius theory) and how it can act as a proton donor (Brønsted–Lowry theory).


Verified Solution

HNO_2 is an Arrhenius acid because it dissociates in water to produce H^+ ions:

\mathrm{HNO}_2(a q) \rightleftharpoons \mathrm{H}^{+}(a q)+\mathrm{NO}_2^{-}(a q)

Nitrous acid is a Brønsted–Lowry acid because it acts as a proton donor when it dissociates, transferring a proton to water to give the hydronium ion, H_3O^+:

The conjugate base of HNO_2 is NO_{2}^{-}, the species that remains after HNO_2 has lost a proton

working example 14.1