Which ONE of the following is an oxidation–reduction reaction? A) PbCO3(s) + 2 HNO3(aq) ––––> Pb(NO3)2(aq) + CO2(g) + H2O(l) B) Na2O(s) + H2O(l) –––> 2 NaOH(aq) C) SO3(g) + H2O(l) ––––> H2SO4(aq) D) CO2(g) + H2O(l) ––––> H2CO3(aq) E) C2H4(g) + H2(g) ––––> C2H6(g)

E) C₂H₄(g) + H₂(g) ⇒ C₂H₆(g)

Explanation:

Which ONE of the following is an oxidation–reduction reaction?

A) PbCO₃(s) + 2 HNO₃(aq) ⇒ Pb(NO₃)₂(aq) + CO₂(g) + H₂O(l). NO. All the elements keep the same oxidation numbers.

B) Na₂O(s) + H₂O(l) ⇒ 2 NaOH(aq). NO. All the elements keep the same oxidation numbers.

C) SO₃(g) + H₂O(l) ⇒ H₂SO₄(aq). NO. All the elements keep the same oxidation numbers.

D) CO₂(g) + H₂O(l) ⇒ H₂CO₃(aq). NO. All the elements keep the same oxidation numbers.

E) C₂H₄(g) + H₂(g) ⇒ C₂H₆(g). YES. C is reduced and H is oxidized.