If the activation energy required for a chemical reaction were reduced, what would happen to the rate of the reaction?
A. The rate would increase.
B. The rate would decrease.
C. The rate would remain the same.
D. The rate would be zero.
Answer (2)
The problem explores the relationship between activation energy and reaction rate.
The Arrhenius equation, k = A e − E a / RT , relates the rate constant k to the activation energy E a .
Reducing E a increases the term − E a / RT , which in turn increases e − E a / RT .
Since k is proportional to e − E a / RT , reducing E a increases the rate constant and thus the reaction rate. The final answer is: The rate would increase.
Explanation
Understanding the Problem The question asks about the effect of reducing the activation energy on the rate of a chemical reaction. We need to determine whether the rate increases, decreases, remains the same, or becomes zero.
Recalling the Arrhenius Equation The Arrhenius equation describes the relationship between the rate constant ( k ) of a reaction and the activation energy ( E a ): k = A e − E a / RT where:
A is the pre-exponential factor,
R is the gas constant,
T is the temperature.
Analyzing the Effect of Reduced Activation Energy We are given that the activation energy E a is reduced. Let's analyze how this affects the rate constant k .
The term − E a / RT appears in the exponent. If E a decreases, then − E a / RT becomes less negative, meaning it increases.
Considering the Exponential Term The exponential function e x is an increasing function. Therefore, if − E a / RT increases, then e − E a / RT also increases.
Concluding the Effect on the Rate Constant Since k = A e − E a / RT , and A is a constant, if e − E a / RT increases, then the rate constant k increases. An increase in the rate constant means the reaction rate increases.
Final Answer Therefore, if the activation energy required for a chemical reaction is reduced, the rate of the reaction would increase.
Examples
In the food industry, enzymes are used to speed up reactions like cheese production or bread making. By reducing the activation energy of these reactions, the production process becomes faster and more efficient, leading to higher yields and lower costs. Similarly, in the development of new drugs, catalysts are used to lower the activation energy of key reactions, accelerating the discovery and manufacturing of life-saving medications. Understanding the relationship between activation energy and reaction rate is crucial for optimizing various industrial and scientific processes.
Reducing the activation energy of a chemical reaction increases the rate of that reaction by making it easier for reactants to collide with sufficient energy. This is explained by the Arrhenius equation, which shows that as activation energy decreases, the rate constant increases. Therefore, the correct answer is A: The rate would increase.
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