Important Chemical Reactions for Class 12 Chemistry: Quick Revision for 2025 Board Exams

Important Chemistry Reactions for Class 12: CBSE Class 12 students can refer to this list of key organic chemistry reactions to aid their preparation. It includes essential reactions like addition, substitution, and elimination, along with examples such as esterification and alkylation. Mastering these reactions is crucial for understanding core concepts and performing well in exams.

Feb 25, 2025, 16:38 IST

Get here Important Chemical Reactions for Class 12 Chemistry, quick revision for CBSE Board Exam 2024

CBSE Class 12 Important Chemical Reactions:The CBSE Class 12 Chemistry exam for 2025 is scheduled for February 27, 2025, from 10:30 a.m. to 1:30 p.m. The exam will cover physical, inorganic, and organic chemistry, so it’s important for students to revise all these sections thoroughly. Being familiar with key reactions in chemistry will save time during the exam and help you answer questions more efficiently.

This article provides a quick revision guide with all the important organic chemistry reactions for Class 12. Students can easily go through these reactions to revise them quickly and effectively. Don’t wait—start your revision now to ensure you're fully prepared!

Important Reactions for Class 12 Chemistry

Gattermann Reaction:

The Gattermann reaction transforms aromatic compounds into aldehydes using hydrogen cyanide, hydrogen chloride, and a catalyst (aluminium chloride or zinc chloride).

Sandmeyer Reaction:

Aromatic diazonium salts react with CuCl or CuBr to yield haloarenes (chlorobenzene or bromobenzene). It's a key step in synthesising various aryl halides from aryl diazonium salts.

Balz-Schiemann Reaction:

The method of preparing arene-diazonium chloride with fluoroboric acid. In this reaction, the arene diazonium fluoroborate is precipitated and decomposes to yield aryl fluoride on heating.

Swarts Reaction:

When alkyl chloride is heated with a metallic fluoride like AgF, Hg2F2, or SbF3, alkyl fluorides are formed.

Finkelstein Reaction:

Alkyl iodides are prepared easily by reacting alkyl chlorides with Nal in dry acetone.

Wurtz Reaction:

The reaction of Alkyl halides reacts with sodium with dry ether to get hydrocarbons that include the double number of carbon atoms present in the alkyl halide.

Friedel-Crafts alkylation Reaction:

Reaction of benzene with an alkyl halide in the presence of anhydrous aluminium chloride to give Alkylbenzene.

Fitting Reaction:

The reaction of aryl halides in the presence of sodium in dry ether gives analogous compounds where two aryl groups joined.

Friedel-Crafts acylation reaction:

Friedel-Crafts acylation is a chemical reaction that involves the introduction of an acyl group onto an aromatic ring using a Lewis acid catalyst.

Reimer-Tiemann Reaction:

Reaction of phenol with chloroform in the presence of sodium hydroxide to introduce -CHO group at the ortho position of the benzene ring. It results in the formation of salicylaldehyde.

Kolbe’s Reaction

The reaction of phenol with sodium hydroxide gives sodium phenoxide which further reacts with carbon dioxide in an acidic medium to give 2-hydroxybenzoic acid (Salicylic acid).