Question

Rate law for the reaction, \( NO_{2(g)} + CO_{g} \rightarrow NO_{(g)} + CO_{2(g)} \) is as \( R = k[NO_{2}]^2 \). What is the order of reaction w.r.t. CO?

• A. Zero
• B. 1
• C. 1.5
• D. 2

Hint:

If a reactant is missing from the rate law expression, the reaction is zero-order with respect to that reactant.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The order of a reaction with respect to a specific reactant is the exponent of its concentration in the experimentally determined rate law equation.
Step 2: Key Formula or Approach:
General rate law expression: \( R = k[A]^{x}[B]^{y} \).
Here, order w.r.t. A is \( x \) and order w.r.t. B is \( y \).
Step 3: Detailed Explanation:
The given rate law is:
\[ R = k[NO_{2}]^{2} \]
This expression can be written as:
\[ R = k[NO_{2}]^{2}[CO]^{0} \]
Comparing this with the general form, we see that the power to which the concentration of CO is raised is 0.
Therefore, the order of the reaction with respect to CO is 0 (zero).
Step 4: Final Answer:
The order of the reaction with respect to CO is zero.