When propene is treated with bromine water, Br2(l), in the presence of carbon tetrachloride as a catalyst, the product is:
Question 1 options:
a) 1,2–dibromopropane
b) 2,2–dibromopropane
c) 2–bromopropane
d) 1–bromopropane
e) none of these
The correct answer is d) 1-bromopropane.
the product is 1,2-dibromopropane?
Apologies for the confusion in my previous response. You are correct, when propene is treated with bromine water in the presence of carbon tetrachloride as a catalyst, the major product is indeed 1,2-dibromopropane. So the correct answer is a) 1,2-dibromopropane.
To determine the product formed when propene is treated with bromine water in the presence of carbon tetrachloride as a catalyst, we need to consider the reaction mechanism.
In the presence of a catalyst, propene will react with bromine water through an electrophilic addition reaction. This reaction involves the nucleophilic attack of bromine on the carbon-carbon double bond of propene.
Step 1: Bromine water dissociates to form bromine cations (Br+) and bromide anions (Br-).
Br2(l) ⟶ Br+(aq) + Br-(aq)
Step 2: The pi bond of propene acts as a nucleophile and attacks the bromine cation. This leads to the formation of a cyclic bromoalkane intermediate.
CH2=CHCH3 + Br+ ⟶ CH2CH(CH3)Br
Step 3: The cyclic bromoalkane intermediate undergoes proton transfer with bromide anions to form the final product.
CH2CH(CH3)Br + Br- ⟶ CH2CH(CH3)Br2
The product formed is 2,2-dibromopropane (option b).
To determine the product formed when propene reacts with bromine water in the presence of carbon tetrachloride as a catalyst, we need to consider the mechanism of the reaction.
Propene is an unsaturated hydrocarbon that can undergo an addition reaction with bromine. In the presence of bromine, the double bond in propene breaks, and each carbon atom forms a new bond with a bromine atom. This results in the addition of bromine to the propene molecule.
The reaction proceeds as follows:
Step 1: The reaction starts with the addition of bromine to one of the carbon atoms in the double bond, forming a bromonium ion intermediate.
Step 2: The bromonium ion intermediate reacts with water (from the bromine water) to form an alcohol intermediate.
Step 3: The alcohol intermediate reacts with bromine to form the final product, which is a brominated compound.
Based on the given options, we can determine the product.
Option a) 1,2–dibromopropane: This compound has two bromine atoms added to adjacent carbons of the propene molecule. This corresponds to the first step of the reaction mechanism.
Option b) 2,2–dibromopropane: This compound has two bromine atoms added to the same carbon, resulting in a tertiary carbon. This is not possible based on the mechanism.
Option c) 2–bromopropane: This compound has one bromine atom added to one carbon atom of propene. This corresponds to the first step of the reaction mechanism.
Option d) 1–bromopropane: This compound has one bromine atom added to one carbon atom of propene. This corresponds to the first step of the reaction mechanism.
Based on the mechanism and the given options, the correct answer is either option c) 2–bromopropane or option d) 1–bromopropane, since only one bromine atom is added to the propene molecule.
To confirm the correct answer, it is advisable to consult additional sources or references and verify the specific conditions and reactions involved in the given reaction.