Answer to Question #150320 in Organic Chemistry for Dan Henry C. Oriola

Question

Formic Acid, Acetic Acid, Propionic Acid, Butyric Acid reaction with (K2Cr2O7) and reaction with (Tollen’s Reagent).

Answer 1

Formic acid reaction with potassium permanganate

$Cr_2 O_7 + 8H + 3HCOOH → 2Cr_3 + 3CO_2 + 7H_2 O$

Formic acid is not a true acid, hence it reduces Tollen's reagent to metallic silver.

Acetic acid reaction with potassium permanganate

$K_2Cr_2O_7 + 8CH_3COOH → 2CH_3COOK + 2(CH_3COO)3Cr + 4H_2O + \frac{3}{2}O_2$

Acetic acid, propionic acid and butyric acid do not react with Tollen's reagent.