Oxidation test with acidified K2Cr2O7 distinguishes alcohol types

Steps:

• Acidified K2Cr2O7 oxidizes primary/secondary alcohols and aldehydes, changing from orange to green.
• Plant compounds A, B, C are primary or secondary alcohols, undergoing oxidation with color change.
• Compound D is a tertiary alcohol, resisting oxidation.
• Thus, D shows no color change, differing from the others.

Why D is correct:

• Tertiary alcohols lack a hydrogen on the carbon bearing the OH group, preventing oxidation per the mechanism requiring H abstraction.

Why the others are wrong:

• A: Primary alcohol oxidizes to aldehyde then carboxylic acid, causing color change.
• B: Secondary alcohol oxidizes to ketone, causing color change.
• C: Aldehyde oxidizes to carboxylic acid, causing color change.

Final answer: D