Under Cr2O7^2-/H+ reflux, oxidation of a primary alcohol yields which product?

Master NCEA Level 3 Organic Chemistry Reaction Schemes. Prepare with multiple choice questions, complete with hints and detailed explanations. Ace your exam with our comprehensive tools!

Multiple Choice

Under Cr2O7^2-/H+ reflux, oxidation of a primary alcohol yields which product?

Strong acidic dichromate under reflux is a very oxidative environment for primary alcohols. The alcohol first forms a chromate ester and is oxidized to an aldehyde, but because the conditions are harsh and heating continues, that aldehyde is further oxidized to a carboxylic acid. The Cr(VI) is reduced to Cr(III) during the process, which you’d often notice as a color change. So, under these conditions, the primary alcohol ends up as a carboxylic acid. In milder or selective oxidations you could see an aldehyde, and secondary alcohols would give ketones, but the reflux with strong oxidant pushes to the carboxylic acid.

Strong acidic dichromate under reflux is a very oxidative environment for primary alcohols. The alcohol first forms a chromate ester and is oxidized to an aldehyde, but because the conditions are harsh and heating continues, that aldehyde is further oxidized to a carboxylic acid. The Cr(VI) is reduced to Cr(III) during the process, which you’d often notice as a color change. So, under these conditions, the primary alcohol ends up as a carboxylic acid. In milder or selective oxidations you could see an aldehyde, and secondary alcohols would give ketones, but the reflux with strong oxidant pushes to the carboxylic acid.

More practice questions