Question

The oxidation of methanol to formaldehyde can be accomplished by reaction with chromic acid: 6H+ + 3CH3OH + 2H2CrO4 → 3CH2O + 2Cr3+ + 8 H2O(l) The reaction can be studied with the stable isotope tracer 18O and mass spectrometry. When a small amount of CH318OH is present in the alcohol reactant, CH218O forms. When a small amount of H2Cr18O4 is present, H218O forms. Does chromic acid or methanol supply the O atom to the aldehyde?

Answer 1

Chromic acid supplies the oxygen atom to the aldehyde.

Step-by-step explanation:

The oxidation of methanol to formaldehyde can be accomplished by reaction with chromic acid: 6H+ + 3CH3OH + 2H2CrO4 → 3CH2O + 2Cr3+ + 8 H2O(l). In this reaction, chromic acid supplies the oxygen atom to the aldehyde, which is evidenced by the formation of H218O when a small amount of H2Cr18O4 is present in the reaction. Additionally, the oxidation of methanol involves the breaking of the C-H bond and the formation of C-O and O-H bonds as the oxygen atom is incorporated into the formaldehyde product.