Determine whether each change represents oxidation or reduction. 1) CH3CHO to CH3CH2OH 2) CH3OH to CH4 3) N2H4to N2 4) gain of electrons 5) NO-2 to NH3 6) NAD+ to NADH 7) CH4 to Co2 8) Ag+ to Ag

1) oxidation

2) Reduction

3) Oxidation

4) Reduction

5) Reduction

6) Reduction

7) Oxidation

8) Reduction

Explanation:

Oxidation is said to have taken place when there is a positive change in the oxidation number while reduction is said to have taken place when there is a decrease in the oxidation number.

The change from CH3CHO to CH3CH2OH represents on oxidation reaction.

The change from CH3OH to CH4 is a reduction because the oxidation number of carbon changes from +2 to -4.

The change from N2H4to N2 is an oxidation because the oxidation number of nitrogen increases from -2 to 0.

The gain in electrons is a reduction because the gain of electron leads to a decrease in oxidation number.

The change from NO- 2 to NH3 is a reduction because the oxidation number of nitrogen changes from +4 to -3.

The change from NAD+ to NADH is a reduction since NAD+ is the oxidized form of the enzyme while NADH is the reduced form of the enzyme.

The change from CH4 to Co2 is an oxidation because the oxidation number of carbon changes from -4 to + 4.

The change from Ag+ to Ag is a reduction because it involves the gain of one electron and a consequent decrease in oxidation number.