Consider this three-step mechanism for a reaction: Cl 2 (g) k 1 ⇌k 2 2 Cl (g) Fast Cl (g) + CHCl 3 (g) →k 3 HCl (g) + CCl 3 (g) Slow Cl (g) + CCl 3 (g) →k 4 CCl 4 (g) Fast a. What is the overall reaction?

Hello everyone today. We are being asked to write an overall equation for the overall reaction using the above mechanism. So we have step one, step two and step three. So the first thing you want to do is you want to write these steps out? So we'll do just that will say we have to gas reacting to form two most of bromine bromine gas. We also have that bro mean gas forming with methane in the gas form to form hbr which is a strong acid in the gas form and Methane or methyl group in the gas form. And then we have that CH three reacting with our roaming from earlier To form this CH three be our product. And so we want to remember a couple of rules. The first one is that the same species? On the same side they're going to add and the same species this is going to be the reverse on different sides. So different sides, they are going to go ahead and subtract using that rule we can go ahead and proceed, we see that we have a we have one bro man on the right on the first equation and we have one brunette on the left for the second equation. Therefore they're going to cancel out. We also see in a second equation we have a CH three on the right of the arrow and we also have a CH three on the left of the arrow. Of the subsequent reaction? We were left with one bro mean in the first equation since we had to and only got rid of one. However, notice how the third reaction also has a bro mean, so we can go ahead and get rid of that second bro mean, and thus we are left with the remaining equation that we have our bro mean, gas, BR two gas plus our methane CH four, also in the gas, and that is going to go ahead and form CH three B are in our gas form as well as H. B. R. In the gas form as well. I hope this helped, and until next time.

Ch.14 - Chemical Kinetics

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Tro 4th Edition

Ch.14 - Chemical Kinetics

Problem 77a

Chapter 14, Problem 77a

Consider this three-step mechanism for a reaction:
Cl₂ (g) k₁⇌k₂ 2 Cl (g) Fast
Cl (g) + CHCl₃ (g) →k₃ HCl (g) + CCl₃ (g) Slow
Cl (g) + CCl₃ (g) →k₄ CCl₄ (g) Fast
a. What is the overall reaction?

Verified step by step guidance

Identify the reactants and products in each step of the mechanism. For the first step, the reactants are Cl2 and the products are 2 Cl. In the second step, the reactants are Cl and CHCl3, and the products are HCl and CCl3. In the third step, the reactants are Cl and CCl3, and the product is CCl4.

Determine the intermediates by identifying species that appear as products in one step and reactants in another. Here, Cl and CCl3 are intermediates as they are produced in one step and consumed in another.

Cancel out the intermediates from the overall reaction. Since Cl and CCl3 are intermediates, they should not appear in the final balanced equation.

Write the overall reaction by combining the remaining reactants and products, ensuring to balance the equation. Start with the initial reactants that are not intermediates and include the final products that are not intermediates.

Check the stoichiometry of the final equation to ensure that the number of atoms of each element is the same on both sides of the equation.

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Key Concepts

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

Reaction Mechanism

A reaction mechanism is a step-by-step description of how a chemical reaction occurs at the molecular level. It outlines the individual elementary steps that lead to the overall reaction, including the formation and consumption of intermediates. Understanding the mechanism helps in predicting the rate and outcome of the reaction.

Elementary Steps

Elementary steps are the individual reactions that make up a reaction mechanism. Each step represents a single molecular event, such as the collision of reactants or the formation of products. The rate of the overall reaction is often determined by the slowest elementary step, known as the rate-determining step.

Overall Reaction

The overall reaction is the net equation that summarizes the reactants and products of a chemical process, derived from the individual elementary steps. It reflects the stoichiometry of the reaction and provides insight into the conservation of mass. To find the overall reaction, one must combine the elementary steps while canceling out any intermediates.