Final answer:
The classifications of the given reactions are as follows: a) Acid-base reaction b) Acid-base reaction c) Oxidation-reduction reaction d) Acid-base reaction.
Step-by-step explanation:
The following reactions can be classified as:
a) Acid-base reaction: 2HCl + Zn → ZnCl₂ + H₂
b) Acid-base reaction: NaOH + HCl → NaCl + H₂O
c) Oxidation-reduction reaction: 2H₂O → 2H₂ + O₂
d) Acid-base reaction: HNO₃ + KOH → KNO₃ + H₂O
In an acid-base reaction, an acid reacts with a base to produce a salt and water. In an oxidation-reduction reaction, electrons are transferred between reactants. In the given reactions, the first two involve the reaction of an acid (HCl) with a base (Zn and NaOH) to produce salts and water, indicating acid-base reactions. The third reaction involves the decomposition of water into hydrogen and oxygen gases, indicating an oxidation-reduction reaction. The fourth reaction involves the reaction of an acid (HNO₃) with a base (KOH) to produce a salt and water, indicating an acid-base reaction.