Question

Which of the following is an oxidation-reduction reaction? Fe2O3 + 3CO mc009-1.jpg 2Fe + 3CO2 CuSO4 + 2NaOH mc009-2.jpg Cu(OH)2 + Na2SO4 2NaOH + H2CO3 mc009-3.jpg Na2CO3 + 2NaOH Pb(NO3)2 + Na2SO4 mc009-4.jpg 2NaNO3 + PbSO4

Answer 1

Answer: it's A

Step-by-step explanation:

Answer 2

`Fe_(2)O_(3)+3CO\rightarrow 2Fe+3CO_(2)` is an oxidation-reduction reaction.

Step-by-step explanation:

In an oxidation-reduction reaction, the oxidation number of some elements must change during reaction.

`Fe_(2)O_(3)+3CO\rightarrow 2Fe+3CO_(2)` represents an oxidation-reduction reaction.

oxidation number

Fe in
`Fe_(2)O_(3)` +3

Fe in Fe 0

C in CO +2

C in
`CO_(2)` +4

SO, oxidation number of Fe decreases during reaction. Hence
`Fe_(2)O_(3)` is being reduced. Also, oxidation number of C increases during reaction. Hence CO is being oxidized.

In all other given reactions, oxidation number of elements are not changed during reaction. Hence they are not oxidation-reduction reaction.