Answer:
B and C
Explanation:
(A) AgNO₃ + NaCl → AgCl + NaNO₃
This is a double displacement reaction. It is not a redox reaction because the elements have the same oxidation numbers on both sides.
(B) Cl₂ + H₂O → HClO + HCl
This is a redox reaction.
Cl₂ is oxidized to HClO. The oxidation number of Cl increases from 0 to +1.
Cl₂ is reduced to HCl. The oxidation number of Cl decreases from 0 to -1.
(C) CuO + CO → CO₂ + Cu
This is a redox reaction.
CO is oxidized to CO₂. The oxidation number of C increases from +2 to +4.
CuO is reduced to Cu. The oxidation number of Cu decreases from +2 to 0.
(D) NaOH + HCl → NaCl + H₂O
This is a double displacement reaction. It is not a redox reaction because the elements have the same oxidation numbers on both sides.
