Question

The following data was obtained for chemical reaction given below at 975 K: 

The order of the reaction with respect to NO is _________. (Integer answer) 
 

Hint:

If doubling the concentration doubles the rate, the order is 1. If it quadruples the rate, the order is 2. If it has no effect, the order is 0.

Answer 1

Correct Answer: 1

Step 1: Understanding the Concept:
The order of a reaction is determined experimentally by observing how the rate changes as the concentration of one reactant is varied while keeping the others constant.
Step 2: Key Formula or Approach:
\[ \text{Rate} = k [NO]^m [H_2]^n \]
Step 3: Detailed Explanation:
1. Compare Experiments (A) and (B):
The concentration of \([H_2]\) is constant at \(8 \times 10^{-5} \text{ M}\).
Concentration of \([NO]\) triples from \(8 \times 10^{-5}\) to \(24 \times 10^{-5}\).
Rate increases from \(7 \times 10^{-9}\) to \(2.1 \times 10^{-8}\) (which is \(21 \times 10^{-9}\)).
Ratio of rates = \(\frac{21 \times 10^{-9}}{7 \times 10^{-9}} = 3\).
Ratio of concentrations = \(\frac{24 \times 10^{-5}}{8 \times 10^{-5}} = 3\).
Since \( (\text{Ratio of conc.})^m = \text{Ratio of rates} \Rightarrow 3^m = 3 \Rightarrow m = 1 \).
Step 4: Final Answer:
The order of the reaction with respect to NO is 1.