Final answer:
The oxidation-reduction reactions among the options given are both (a) PCl₃ with O₂ and (b) Cu with AgNO₃. Reactions (c) involving H₂SO₄ and LiOH, and (d) involving NaOH and Fe(OH)₂, are not redox reactions, with (c) being a neutralization and (d) a double displacement reaction.
Step-by-step explanation:
The question posed is concerned with determining which of the provided chemical reactions are oxidation-reduction reactions, often known as redox reactions. Redox reactions are characterized by the transfer of electrons between substances, leading to changes in the oxidation states of the elements involved.
The reactions are as follows:
- a) PCl₃(s) + 5 O₂(g) → P₄O₁₀(s): This is a redox reaction because the phosphorus in PCl₃ is oxidized from an oxidation state of +3 to +5 in P₄O₁₀.
- b) Cu(s) + 2 AgNO₃(aq) → Cu(NO₃)₂(aq) + 2 Ag(s): Another redox reaction where copper is oxidized from 0 to +2, and silver is reduced from +1 to 0.
- c) H₂SO₄(aq) + 2 LiOH(aq) → Li₂SO₄(aq) + 2 H₂O(l): This is not a redox reaction but an acid-base neutralization reaction.
- d) 2 NaOH(aq) + Fe(OH)₂(s) → Na₂Fe(OH)₄(aq) + H₂O(l): This is not a typical redox reaction; it is a double displacement reaction.
Thus, the oxidation-reduction reactions from the list provided are examples a) and b).