The following question is based on Chemistry Outside the...

The following question is based on Chemistry Outside the Classroom 13.1. The reaction of hydrogen and bromine appears to follow the mechanism shown, $$\begin{aligned}\mathrm{Br}_{2} & \longrightarrow 2 \mathrm{Br}^{*} \\\mathrm{Br} \cdot+\mathrm{H}_{2} & \longrightarrow \mathrm{HBr}+\mathrm{H} \\\mathrm{H} \cdot+\mathrm{Br}_{2} & \longrightarrow \mathrm{HBr}+\mathrm{Br} \\2 \mathrm{Br} \cdot &\longrightarrow\mathrm{Br}_{2}\end{aligned}$$ (a) Identify the initiation step in the mechanism. (b) Identify any propagation steps. (c) Identify the termination step. (d) The mechanism also contains the reaction $$\mathrm{H} \cdot+\mathrm{HBr} \longrightarrow \mathrm{H}_{2}+\mathrm{Br}$$ How does this reaction affect the rate of formation of $\mathrm{HBr}$ ?

The following question is based on Chemistry Outside the Classroom 13.1. The reaction of hydrogen and bromine appears to follow the mechanism shown, $$\begin{aligned}\mathrm{Br}_{2} & \longrightarrow 2 \mathrm{Br}^{*} \\\mathrm{Br} \cdot+\mathrm{H}_{2} & \longrightarrow \mathrm{HBr}+\mathrm{H} \\\mathrm{H} \cdot+\mathrm{Br}_{2} & \longrightarrow \mathrm{HBr}+\mathrm{Br} \\2 \mathrm{Br} \cdot &\longrightarrow\mathrm{Br}_{2}\end{aligned}$$
(a) Identify the initiation step in the mechanism.
(b) Identify any propagation steps.
(c) Identify the termination step.
(d) The mechanism also contains the reaction
$$\mathrm{H} \cdot+\mathrm{HBr} \longrightarrow \mathrm{H}_{2}+\mathrm{Br}$$ How does this reaction affect the rate of formation of $\mathrm{HBr}$ ?

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Chain Inhibition

Chain inhibition refers to side reactions that reduce the number of radicals available for propagation. When a reactive radical interacts with a product or another species in a non-productive way, it can slow down the rate of product formation by interrupting the sustained chain reaction process.

Initiation Step

This is the part of a chain reaction where radicals are first generated, typically by the homolytic cleavage of a covalent bond. The initiation step is crucial because it produces the reactive species (radicals) that will drive the subsequent steps of the reaction.

Propagation Steps

Propagation steps are the successive reactions in a chain mechanism where radicals react with stable molecules, forming new radicals and products. These steps sustain the chain reaction by continuously regenerating reactive radicals, thereby allowing the reaction to proceed.

Termination Step

The termination step involves reactions in which radicals combine to form stable, non-radical products. This process removes reactive radicals from the system, ultimately slowing or stopping the chain reaction as fewer radicals are available to sustain the propagation.

Transcript

Please give Ace some feedback