Mechanism of preparation of carboxylic acid from primary alcohols
Answers
Primary alcohols, as well as aldehydes, can undergo oxidation reaction to form corresponding carboxylic acids with the help of oxidizing agents such as potassium permanganate (KMnO4 for neutral or acidic or alkaline media), chromium trioxide (CrO3-H2SO4-Jones reagent), and potassium dichromate (K2Cr2O7 – acidic media).
Primary alcohol undergoes oxidation to produce carboxylic acid on the addition of the oxidizing agents. Therefore, the oxidation of primary alcohols produces aldehydes which further repeat the oxidation to produce carboxylic acids. The strong oxidizing agents including potassium dichromate, potassium permanganate, and chromium trioxide can readily oxidize the aldehyde to form carboxylic acids.
However, mild oxidizing agents can only undergo one step and convert the primary alcohols into aldehydes. Example of mild oxidizing agents includes manganese dioxide (MnO 2) and Tollen’s reagent [Ag(NH 3) 2 +OH −]. Hence, they are not strong enough to undergo oxidation twice. Therefore, the mild oxidizing agents are used for converting aldehydes into carboxylic acids.
It is important to remember that acidified oxidizing agents like potassium dichromate and Jones reagent lead to the formation of esters in a small amount. Therefore, it is preferable to use neutral or alkaline agents such as potassium permanganate for this preparation method.
Answer:
preparation from primary alcohols
Explanation:
Primary alcohols, as well as aldehydes, can undergo oxidation reaction to form corresponding carboxylic acids with the help of oxidizing agents such as potassium permanganate (KMnO4 for neutral or acidic or alkaline media), chromium trioxide (CrO3-H2SO4-Jones reagent), and potassium dichromate (K2Cr2O7 – acidic media).