Which reaction can be classified as reduction? A - Scottish Highers Chemistry - Question 11 - 2019

To determine which reaction is classified as reduction, we need to identify the change in oxidation state of the reactants and products.

Reduction involves the gain of electrons or the decrease in oxidation state. In option C, butan-2-one (a ketone) is being reduced to butan-2-ol (an alcohol). This reaction involves the addition of hydrogen (H₂) or the removal of oxygen, resulting in a decrease in oxidation state, hence classifying it as reduction.

In contrast, the other options involve oxidation processes, where either alcohols are being converted to acids or no change in oxidation states occurring (as in the case of D, which is a conversion of an alcohol to a ketone where there is an increase in oxidation state).