Skip to main content
Ch. 5 - Chemical Reaction Analysis: Thermodynamics and Kinetics
Mullins - Organic Chemistry: A Learner Centered Approach 1st Edition
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook
All textbooksMullins 1st EditionCh. 5 - Chemical Reaction Analysis: Thermodynamics and KineticsProblem 52f
Chapter 4, Problem 52f

Predict the product(s) of the following halogenation reactions. Only one equivalent of the halogen is used in each case. If the reaction proceeds selectively, indicate this by only drawing the major product. If the reaction is not selective, draw all possible products.
(f)

Verified step by step guidance
1
Step 1: Recognize that the reaction involves bromination under heat, which suggests a radical halogenation mechanism. Bromine (Br₂) selectively reacts with the most stable radical intermediate.
Step 2: Identify the structure of the given alkane. The molecule contains a tertiary carbon, secondary carbons, and primary carbons. Bromination will favor the formation of the most stable radical intermediate, which is the tertiary radical.
Step 3: Generate the radical intermediates by abstracting a hydrogen atom from each type of carbon (primary, secondary, tertiary). Compare the stability of these radicals. Tertiary radicals are the most stable due to hyperconjugation and inductive effects.
Step 4: Predict the major product by attaching the bromine atom to the carbon that forms the most stable radical (the tertiary carbon). This is the selective product of the reaction.
Step 5: If the reaction is not perfectly selective, consider minor products formed by bromination at secondary or primary carbons. However, the major product will dominate due to the high selectivity of bromine for the most stable radical.

Verified video answer for a similar problem:

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.

Halogenation Reactions

Halogenation is a chemical reaction where a halogen atom (such as chlorine or bromine) is introduced into a compound, typically an alkane or alkene. This process can occur through radical mechanisms or electrophilic addition, depending on the substrate and conditions. Understanding the mechanism is crucial for predicting the products formed, especially in terms of regioselectivity and stereochemistry.
Recommended video:
Guided course
03:45
Halogenation Mechanism

Selectivity in Reactions

Selectivity refers to the preference of a chemical reaction to produce one product over others when multiple products are possible. In halogenation, selectivity can be influenced by factors such as the stability of the intermediates and the nature of the substrate. Recognizing whether a reaction is selective or not helps in determining which products to draw, focusing on the major product when applicable.
Recommended video:
Guided course
10:08
Radical selectivity:Alcoholics Anonymous Version

Product Prediction

Predicting the products of a chemical reaction involves applying knowledge of reaction mechanisms, stability of intermediates, and the nature of the reactants. In halogenation, one must consider the type of halogen used, the structure of the organic compound, and the reaction conditions. This skill is essential for accurately representing the expected outcomes of the reaction, including any possible isomers.
Recommended video:
Guided course
03:13
Predict the Products
Related Practice
Textbook Question

Predict the product(s) of the following halogenation reactions. Only one equivalent of the halogen is used in each case. If the reaction proceeds selectively, indicate this by only drawing the major product. If the reaction is not selective, draw all possible products.

(e)

1
views
Textbook Question

Draw a reaction coordinate diagram, making sure to label reactants (R), products (P), intermediates (I), transition states (‡), activation energies ( Ea) , and ∆G°, for each of the following.

(a) an exothermic, one-step reaction

1
views
Textbook Question

For each of the reaction coordinate diagrams shown, (i) indicate the number of steps in the reaction, (ii) label the intermediates, (iii) identify the rate-determining step, and (iv) tell whether Keq is greater than, less than, or equal to zero.

(a)

1
views
Textbook Question

Draw a reaction coordinate diagram, making sure to label reactants (R), products (P), intermediates (I), transition states (‡), activation energies ( Ea) , and ∆G°, for each of the following.

(b) an exothermic, two-step reaction where the second step is rate-determining

1
views
Textbook Question

For each set of reactive intermediates, rank them in order of reactivity (1 = most reactive).

(c)

5
views
Textbook Question

Predict the product(s) of the following halogenation reactions. Only one equivalent of the halogen is used in each case. If the reaction proceeds selectively, indicate this by only drawing the major product. If the reaction is not selective, draw all possible products.

(b)