Final answer:
The given chemical reaction is classified as an acid-base neutralization reaction where an acid and a base produce water and a salt.
Step-by-step explanation:
The reaction HNO₃(aq) + KOH(aq) → KNO₃(aq) + H₂O(l) is best classified as an acid-base neutralization reaction. In a neutralization reaction, an acid and a base react to form water and a salt. No oxidation number changes occur, so it is not an oxidation-reduction reaction. There is also no formation of an insoluble compound, which would indicate a precipitation reaction. Finally, since no single element replaces another in a compound, it is not a single replacement reaction.