Skip to main content
Ch.21 - Organic Chemistry
Chapter 21, Problem 48a,b,d

List all the possible products for each alkane substitution reaction. (Assume monosubstitution.) a.CH4 +Cl2 → b. CH3CH2Br + Br2 → d. CH3CHBr2 + Br2

Verified step by step guidance
1
Identify the type of reaction: This is a halogenation reaction involving an alkane and bromine (Br2).
Recognize that the reaction involves monosubstitution, meaning only one hydrogen atom in the alkane will be replaced by a bromine atom.
Determine the structure of the starting compound: CH3CHBr2 is a dibromoethane, specifically 1,1-dibromoethane.
Consider the possible sites for substitution: In 1,1-dibromoethane, the hydrogen atoms on the carbon atoms can be replaced by bromine.
List the possible monosubstitution products: Replace one hydrogen atom with a bromine atom to form different isomers, such as CH2BrCHBr2 (1,1,2-tribromoethane).

Verified Solution

Video duration:
3m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Alkane Substitution Reactions

Alkane substitution reactions involve the replacement of one hydrogen atom in an alkane with another atom or group, typically through a free radical mechanism. In these reactions, alkanes react with halogens (like Br2) to form haloalkanes. The process usually requires heat or light to initiate the formation of free radicals, which are highly reactive species that drive the substitution.
Recommended video:
Guided course
05:07
Naming Alkanes with Substituents Example

Free Radical Mechanism

The free radical mechanism is a multi-step process that includes initiation, propagation, and termination steps. In the initiation step, a halogen molecule (e.g., Br2) is broken into two free radicals, which can then react with alkanes. During propagation, these radicals react with alkane molecules to form new radicals and products, continuing the chain reaction until termination occurs when two radicals combine.
Recommended video:
Guided course
03:06
Reaction Mechanism Overview

Monosubstitution Products

In the context of monosubstitution, only one hydrogen atom in the alkane is replaced by a halogen atom. For the reaction CH3CHBr2 + Br2, the possible products include dibrominated alkanes and brominated alkanes, depending on which hydrogen is substituted. The specific products can vary based on the position of substitution and the stability of the resulting radicals.
Recommended video:
Guided course
00:30
Monosubstituted Benzene