Question

In the reaction, A \( \rightarrow \) products, if the concentration of the reactant is doubled but the rate of reaction remains unchanged, what is the order of the reaction with respect to A?

• A. 1
• B. 2
• C. 0.5
• D. 0

Hint:

In a zero-order reaction, the rate is independent of the concentration of reactants.

Answer 1

The Correct Option is D

Step 1: Rate Law Definition
The general rate law is expressed as: \[ r = k[A]^n \], where \( n \) represents the reaction order. 
Step 2: Condition Analysis 
The provided condition states that when the concentration of \( A \) is doubled, the reaction rate does not change. 
This can be represented mathematically as: \[ r_2 = k[2A]^n \]. Given that the initial rate \( r_1 \) equals the new rate \( r_2 \), we set the equations equal: \[ k[A]^n = k[2A]^n \] 
Step 3: Determining Reaction Order 
Upon division of both sides of the equation: \[ 1 = 2^n \] \[ 2^n = 1 \] \[ n = 0 \] Conclusion: The reaction order is determined to be zero.