WILLER ACADEMY

Aldehydes, Ketones & Carboxylic Acids - Chapter Test

Instructions: This test contains 30 Multiple Choice Questions. Each question has only one correct answer. Select the most appropriate option for each question. You have 45 minutes to complete the test.

Subject: Organic Chemistry

Chapter: Aldehydes, Ketones & Carboxylic Acids

Total Questions: 30

Time Allotted: 45 Minutes

Multiple Choice Questions

1. The IUPAC name of CH₃-CH₂-CHO is:

Propanal Propanone Ethanal Butanal

2. Which of the following compounds will not give a positive iodoform test?

CH₃CH₂OH CH₃COCH₃ CH₃CHO C₆H₅COCH₃

3. Tollen's reagent is used for the detection of:

Aldehydes Alcohols Ketones Carboxylic acids

Important Name Reactions

1. Cannizzaro Reaction

2R-CHO + NaOH → R-CH₂OH + R-COONa

Mechanism: This reaction occurs with aldehydes that lack alpha-hydrogen atoms. In concentrated NaOH, one aldehyde molecule is oxidized to carboxylic acid salt while another is reduced to alcohol.

Example: Formaldehyde (HCHO) undergoes Cannizzaro reaction to form methanol and sodium formate.

2. Aldol Condensation

R-CH₂-CHO + R-CH₂-CHO → R-CH₂-CH(OH)-CH(R)-CHO

Mechanism: Aldehydes or ketones with alpha-hydrogen atoms in dilute NaOH form beta-hydroxy aldehydes (aldol) or beta-hydroxy ketones (ketol).

Example: Acetaldehyde forms 3-hydroxybutanal in aldol condensation.

3. Clemmensen Reduction

R-CO-R' + 4[H] (Zn-Hg/HCl) → R-CH₂-R' + H₂O

Mechanism: Carbonyl group of aldehydes or ketones is reduced to methylene group using zinc amalgam and concentrated hydrochloric acid.

Example: Acetone is reduced to propane by Clemmensen reduction.

4. Wolff-Kishner Reduction

R-CO-R' + N₂H₄ + KOH → R-CH₂-R' + N₂ + H₂O

Mechanism: Carbonyl compounds are reduced to hydrocarbons by heating with hydrazine and potassium hydroxide.

Example: Acetophenone is reduced to ethylbenzene by Wolff-Kishner reduction.

Test Results

0/30

Keep practicing!

Willer Academy - Excellence in Chemistry Education | © 2023 All Rights Reserved