krit.club logo

Aldehydes, Ketones and Carboxylic Acids - Uses of aldehydes and ketones

Grade 12ICSEChemistry

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

Formaldehyde (HCHOHCHO): A 40%40\% aqueous solution of formaldehyde is known as Formalin, which is used for preserving biological specimens and in the manufacture of polymers like Bakelite.

Acetaldehyde (CH3CHOCH_3CHO): Primarily used as a starting material in the manufacture of acetic acid (CH3COOHCH_3COOH), ethyl acetate, vinyl acetate, and various drugs.

Benzaldehyde (C6H5CHOC_6H_5CHO): Used extensively in the perfumery and dye industries, and as a flavoring agent due to its characteristic bitter almond smell.

Acetone (CH3COCH3CH_3COCH_3): A common industrial solvent used for cellulose acetate, lacquers, and resins. It is also the primary component in nail polish removers.

Ketones in industry: Higher ketones like acetophenone (C6H5COCH3C_6H_5COCH_3) and benzophenone (C6H5COC6H5C_6H_5COC_6H_5) are used in the preparation of perfumes and pharmaceuticals.

Flavoring and Fragrance: Many naturally occurring aldehydes and ketones are used for their pleasant odors, such as Vanillin (from vanilla beans) and Cinnamaldehyde (from cinnamon).

📐Formulae

HCHOHCHO

CH3CHOCH_3CHO

C6H5CHOC_6H_5CHO

CH3COCH3CH_3COCH_3

C6H5COCH3C_6H_5COCH_3

RCHOR-CHO

RCORR-CO-R'

💡Examples

Problem 1:

State the composition and one major use of Formalin.

Solution:

Formalin is a 40%40\% aqueous solution of Methanal (HCHOHCHO). It is used for the preservation of biological and anatomical specimens.

Explanation:

Formalin acts as a disinfectant and preservative by cross-linking primary amino groups in proteins through CH2CH_2 linkages, preventing decay.

Problem 2:

Which carbonyl compound is used in the manufacture of Bakelite?

Solution:

Formaldehyde (HCHOHCHO).

Explanation:

Formaldehyde undergoes a condensation polymerization reaction with Phenol (C6H5OHC_6H_5OH) to produce Bakelite, a thermosetting polymer.

Problem 3:

Identify the ketone used as a solvent for cellulose acetate and nitrocellulose.

Solution:

Acetone (Propanone, CH3COCH3CH_3COCH_3).

Explanation:

Acetone is an excellent polar aprotic solvent that effectively dissolves many organic compounds, making it ideal for industrial coatings and cleaning.

Uses of aldehydes and ketones - Revision Notes & Key Formulas | ICSE Class 12 Chemistry