Key Organic Chemistry Reactions for Grade 12
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What is the purpose of Gabriel synthesis?
Preparation of pure primary amines.
What is formed when phthalimide is treated with ethanolic potassium hydroxide?
Potassium salt of phthalimide.
What type of amines cannot be prepared using the Gabriel synthesis?
Aromatic primary amines.
What does the Hoffmann bromamide degradation reaction produce?
Primary amines.
What is the outcome of the carbylamine reaction?
Formation of isocyanides (carbylamines).
What does Hinsberg’s reagent react with?
Primary and secondary amines.
What is the product when a primary amine reacts with benzenesulphonyl chloride?
N-ethylbenzenesulphonyl amide.
What type of reaction occurs between benzene diazonium chloride and phenol?
Coupling reaction.
What nucleophiles can be introduced into the benzene ring using the Sandmeyer reaction?
Cl, Br, and CN.
What is produced in the Gatterman reaction?
Chlorinated or brominated benzene derivatives.
What does the Finkelstein reaction involve?
Reaction of alkyl chlorides/bromides with NaI in dry acetone.
What does heating an alkyl halide with sodium in dry ether produce?
Hydrocarbons with double the number of carbon atoms.
What is the product of Friedel-Crafts acylation?
Acylbenzene.
What does the Reimer-Tiemann reaction introduce into phenol?
A –CHO group at the ortho position.
What is the Cannizzaro reaction?
A self oxidation and reduction reaction of aldehydes without an α-hydrogen atom.
What type of aldehydes undergo the Cannizzaro reaction?
Aldehydes that do not have an α-hydrogen atom.
What is produced in the Cannizzaro reaction?
Alcohol and carboxylic acid salt.
What does Kolbe electrolysis produce?
Alkanes containing an even number of carbon atoms.
What type of reaction is Kolbe electrolysis?
Decarboxylation reaction.
What is the Hell-Volhard-Zelinsky (HVZ) reaction?
A halogenation reaction of carboxylic acids at the α-position.
What is formed as a result of the Hell-Volhard-Zelinsky reaction?
α-Halocarboxylic acids.
What reagents are used in the Hell-Volhard-Zelinsky reaction?
Chlorine or bromine and red phosphorus.
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Description
Explore essential organic chemistry reactions including Sandmeyer, Gatterman, and Friedel-Crafts. Understand their mechanisms, applications, and differences to enhance your knowledge and performance in Grade 12 chemistry.
Questions
Download Questions1. What is the main product of the Gabriel synthesis?
2. Which reagent is used in the Hinsberg test to distinguish between primary, secondary, and tertiary amines?
3. What is the key characteristic of the carbylamine reaction?
4. What is the result of treating benzene with an alkyl halide in the presence of anhydrous aluminium chloride?
5. Which reagent is used to convert acyl chloride to aldehyde in the Rosenmund reduction?
6. What is formed when phenol reacts with sodium hydroxide and carbon dioxide in acidic medium?
7. What is the product of the Clemmensen reduction of aldehydes and ketones?
8. In the Sandmeyer reaction, which ion is essential for the introduction of Cl, Br, and CN nucleophiles into the benzene ring?
9. Which reaction involves the preparation of alkyl iodides using alkyl chlorides/bromides and NaI in dry acetone?
10. What is the main product when phenol is treated with chloroform in the presence of sodium hydroxide?
Study Notes
Summary of Key Organic Reactions
This document outlines three significant organic reactions: the Cannizzaro Reaction, Kolbe Electrolysis, and the Hell-Volhard-Zelinsky (HVZ) Reaction. Each reaction plays a crucial role in organic synthesis and demonstrates unique mechanisms and products.
Cannizzaro Reaction
- The Cannizzaro Reaction occurs with aldehydes that lack an α-hydrogen atom. When treated with concentrated alkali, one molecule is reduced to an alcohol while another is oxidized to a carboxylic acid salt.
- This reaction exemplifies self-oxidation and reduction, highlighting the importance of specific reactant conditions.
Kolbe Electrolysis
- Kolbe Electrolysis involves the electrolysis of sodium or potassium salts of carboxylic acids in aqueous solution. This process results in the formation of alkanes containing an even number of carbon atoms through decarboxylation.
- It showcases how electrochemical methods can be utilized to synthesize hydrocarbons efficiently.
Hell-Volhard-Zelinsky (HVZ) Reaction
- The HVZ Reaction facilitates the halogenation of carboxylic acids with an α-hydrogen at the α-position when treated with chlorine or bromine in the presence of red phosphorus, yielding α-halocarboxylic acids.
- This reaction emphasizes selective functionalization at specific positions on organic molecules.
Key Takeaways
- The Cannizzaro Reaction is crucial for converting aldehydes without α-hydrogens into valuable alcohols and carboxylic acid salts.
- Kolbe Electrolysis is a powerful method for generating alkanes from carboxylic acid salts via electrochemical processes.
- The HVZ Reaction allows for targeted halogenation of carboxylic acids, expanding synthetic possibilities in organic chemistry.
These reactions are foundational in organic chemistry, providing pathways for synthesizing diverse compounds and enhancing our understanding of molecular transformations.