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 , describes this relationship.
Reducing the activation energy ( E a ) increases the rate constant ( k ).
An increased rate constant leads to an increased reaction rate, so 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 consider how activation energy and reaction rate are related.
Recalling the Arrhenius Equation The relationship between activation energy ( E a ) and the rate constant ( k ) of a reaction is described by the Arrhenius equation: k = A e − E a / RT where:
k is the rate constant
A is the pre-exponential factor
E a is the activation energy
R is the gas constant
T is the temperature
Analyzing the Effect of Reduced Activation Energy We are told that the activation energy E a is reduced. Let's analyze how this affects the rate constant k . In the Arrhenius equation, E a appears in the exponent with a negative sign. Therefore, if E a decreases, the value of − E a / RT increases (becomes less negative).
Determining the Change in Rate Constant Since the exponent − E a / RT increases, the value of e − E a / RT also increases. Because k = A e − E a / RT , an increase in e − E a / RT means that the rate constant k increases.
Concluding the Effect on Reaction Rate The rate of a reaction is directly proportional to the rate constant k . Therefore, if the rate constant k increases, the rate of the reaction also increases.
Final Answer Therefore, if the activation energy required for a chemical reaction is reduced, the rate of the reaction will increase. The correct answer is: O The rate would increase.
Examples
In the food industry, enzymes are used to speed up reactions, such as breaking down starches into sugars. By reducing the activation energy of these reactions, the enzymes allow food processing to occur more quickly and efficiently, leading to faster production times and improved product quality. This principle is also used in the development of new catalysts for various industrial processes, aiming to reduce energy consumption and increase reaction yields.
Reducing the activation energy required for a chemical reaction results in an increased rate of that reaction. This is due to the relationship illustrated by the Arrhenius equation, where a lower activation energy boosts the rate constant. Therefore, the correct answer is A: The rate would increase.
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