Hydrogen bromide is a highly reactive and corrosive gas used mainly as a catalyst for organic reactions. It is produced by reacting hydrogen and bromine gases together.
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(a) What is the order of the reaction with respect to hydrogen, bromine, and overall?
(b) Write the rate expression of the reaction.
(c) Calculate k for the reaction. What are the units for k?
(d) When
(a)
Interpretation:
To determine the order of reaction with respect to BF3, NH3 and overall for the following reaction:
Concept introduction:
Rate of a chemical reaction: It tells us about the speed at which the reactants are converted into products.
Mathematically, rate of reaction is directly proportional to the product of concentration of each reactant raised to the power equal to their respective stoichiometric coefficients.
Let’s say we have a reaction:
Answer to Problem 27QAP
Order of given reaction:
With respect to H2 =1
With respect to Br2 =
Overall =
Explanation of Solution
Given information:
Here the chemical reaction is:
Let’s assume the reaction to be ‘t’ order with respect to H2 and ‘y’ order with respect to Br2.
Then, rate law for experiment 1 in above reaction will be;
And, rate law for experiment 3 in above reaction will be;
Divide (1) by (2) to get value of ‘t’.
Thus, order with respect to Br2 is
Now, rate law for experiment 4 in above reaction will be;
Divide (2) by (3) to get value of ‘y’.
Thus, order with respect to H2 is 1.
And the order of reaction will be:
Thus, overall order of reaction is 2.
(b)
Interpretation:
To write the rate expression for the given reaction.
Concept introduction:
Rate of a chemical reaction: It tells us about the speed at which the reactants are converted into products.
Mathematically, rate of reaction is directly proportional to the product of concentration of each reactant raised to the power equal to their respective stoichiometric coefficients.
Let’s say we have a reaction:
Answer to Problem 27QAP
Rate law expression for above reaction will be;
Explanation of Solution
Here the chemical reaction is:
Order of reaction with respect to H2 = 2
Order of reaction with respect to Br2 =
Let the rate constant be ‘k’.
Then, rate law expression for above reaction will be;
(c)
Interpretation:
To determine the rate constant and its unit for the given reaction.
Concept introduction:
Rate of a chemical reaction: It tells us about the speed at which the reactants are converted into products.
Mathematically, rate of reaction is directly proportional to the product of concentration of each reactant raised to the power equal to their respective stoichiometric coefficients.
Let’s say we have a reaction:
Answer to Problem 27QAP
Rate constant is
Unit of rate constant is
Explanation of Solution
Here the chemical reaction is:
Writing rate law for experiment 1 in above reaction will be;
Hence, the rate constant is
And unit of rate constant is
(d)
Interpretation:
To determine the rate of reaction at given concentration of reactants.
Concept introduction:
Rate of a chemical reaction: It tells us about the speed at which the reactants are converted into products.
Mathematically, rate of reaction is directly proportional to the product of concentration of each reactant raised to the power equal to their respective stoichiometric coefficients.
Let’s say we have a reaction:
Answer to Problem 27QAP
Rate of reaction for given reaction at given conditions is
Explanation of Solution
Here the chemical reaction is:
Rate law expression for above reaction:
Here we have:
[H2 ]=0.421 M
[Br2 ] = 0.215 M
Rate constant =
Plugging values in rate law as:
Hence, the rate of reaction is
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Chapter 11 Solutions
Chemistry: Principles and Reactions
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