Final answer:
The chemical reaction NaNO3 + HCl → NaCl + HNO2 is a double-replacement reaction, where parts of two ionic compounds are exchanged to form new compounds, making the answer C. Double replacement.
Step-by-step explanation:
The reaction NaNO3 + HCl → NaCl + HNO2 is an example of a double-replacement reaction. In a double-replacement reaction, parts of two ionic compounds are exchanged to form two new compounds. This means that the sodium (Na+) from sodium nitrate (NaNO3) and the hydrogen (H+) from hydrochloric acid (HCl) are exchanged, resulting in the formation of sodium chloride (NaCl) and nitrous acid (HNO2).
Considering other types of reactions, such as single-replacement or decomposition, we can rule them out because there is an exchange between two compounds, not the replacement of a single element or the breaking down of a single compound into multiple products. Therefore, the correct answer to the question is C. Double replacement.