Please help me with this Chemistry question.

Question

Chemical reactions fall into two classes: redox (electron exchange occurs), and non-electron transfer. Generally speaking, under which category do each of these reactions fall?

1. Combustion
2. Decomposition
3. Combination
4. acid-base
5. Double Replacement
6. Single Replacement

Answer 1

Combustion - redox (ex: O₂ converted to CO₂)

Decomposition - some are redox (ex: 2H₂O -> 2H₂ + O₂)

Combination - redox (ex: C + O₂ -> CO₂)

Acid-base: non-electron transfer (ex: HCl + NaOH -> NaCl + H₂O which is a proton transfer)

Double replacement: non-electron transfer (ex: AgNO₃ + NaCl -> AgCl + NaNO₃)

Single replacement: redox (ex: Zn + 2HCl -> ZnCl₂ + H₂)