Sample Problems on Zero Order Reactions
Question 1: For a zero-order reaction A →P, if the initial concentration of A is 1.0 M and after 20 seconds, the concentration of A decreases to 0.6 M, calculate the rate constant k.
Solution:
The rate of a zero-order reaction is given by the equation: Rate = -k.
Using the given data, we can calculate the rate constant k as follows:
Rate = (1.0 M – 0.6 M) / 20 s = 0.4 M / 20 s = 0.02 M/s.
Therefore, the rate constant k for this reaction is 0.02 M/s.
Question 2: In a zero-order reaction A → B, if the rate constant k is 0.005 M/s, what will be the concentration of A after 50 seconds if the initial concentration of A is 2.0 M?
Solution:
The concentration of A at any time t in a zero-order reaction is given by the equation:
[A]=[A]0 −kt
Substituting the given values into the equation:
[A]=2.0M−(0.005M/s×50s)=2.0M−0.25M=1.75M.
Therefore, the concentration of A after 50 seconds will be 1.75 M.
Question 3: For a zero-order reaction A →P, if the rate constant k is 0.01 M/s and the initial concentration of A is 3.0 M, calculate the time taken for the concentration of A to decrease to 1.0 M.
Solution:
Using the zero-order reaction equation
[A]=[A]0−kt,
we can rearrange it to find the time t:
t = ([A]0 −[A])/k.
Substituting the given values:
t = (3.0M−1.0M)/0.01M/s = 200s.
Therefore, it will take 200 seconds for the concentration of A to decrease from 3.0 M to 1.0 M in this zero-order reaction.
Zero Order Reaction
Zero Order Reaction is a type of chemical reaction where the reaction rate does not change with variations in the concentration of the reactants. In such reactions, the concentration rates remain constant over time. This type of reaction is characterized by the fact that the concentration of the reactants does not influence the reaction rate.
In this article, we look into What the order of the reaction is, what the zero-order reaction is, definition characteristics, rate law expression, etc.
Table of Content
- What is Order of Reaction?
- What is a Zero Order Reaction?
- Characteristics of Zero Order Reactions
- Rate Law for Zero Order Reactions
- Half-Life Time (t1/2) for Zero Order Reaction
- Zero, First and Second-Order Reactions
- Significance of Zero Order Reactions
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