Chemistry Reaction Kinetics PMC 2021
PMDC Verified Question 44 of 80
Rate = \( k[\text{NO}_{2}] \), the order of this reaction is:
A
Zero
B
Two
C
Three
D
One
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option D: One
Concept:

The overall order of a chemical reaction is calculated directly from its experimental rate law equation.

Solution:

  • The rate law is given as: Rate = \( k[\text{NO}_{2}] \).
  • When no exponent is explicitly written next to a concentration bracket, it is mathematically understood to be 1.
  • The sum of all exponents in this rate law is exactly 1.
  • Therefore, this is a first-order reaction.


Why other options are incorrect:

The exponent is clearly 1, making zero, two, or three mathematically impossible given the explicit formula.

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