In the given reaction:
\[ \text{{NO}}_2^- (aq) + \text{{H}}_2\text{{O}} (l) \rightarrow \text{{HNO}}_2 (aq) + \text{{OH}}^- (aq) \]
the \(\text{{NO}}_2^-\) ion is acting as a proton acceptor because it takes a proton (H\(^{+}\)) from water (\(\text{{H}}_2\text{{O}}\)), which results in the formation of nitrous acid (\(\text{{HNO}}_2\)) and hydroxide ions (\(\text{{OH}}^-\)).
According to the Brønsted-Lowry acid-base theory:
- A Brønsted-Lowry acid is a substance that donates a proton (H\(^+\)), while
- A Brønsted-Lowry base is a substance that accepts a proton (H\(^+\)).
Since \(\text{{NO}}_2^-\) is accepting a proton, it acts as a Brønsted-Lowry base.
Therefore, the correct answer is:
B. Brønsted-Lowry base.
2 answers