Question

For the following reaction:
$NO_{2(g)} + CO_{(g)} \to NO_{(g)} + CO_{2(g)}$, the rate law is: Rate = $k[NO_2]^2$. If $0.1$ mole of gaseous carbon monoxide is added at constant temperature to the reaction mixture which of the following statements is true?

• A. Both $k$ and the reaction rate the reaction rate remain
• B. Both $k$ and the reaction rate increase
• C. Both $k$ and the reaction rate decrease
• D. Only $k$ increases, the reaction rate remain the same
• E. Only the reaction rate increases; $k$ remains the same

Answer 1

Answer: (A)

$NO _{2}(g)+ CO (g) \longrightarrow NO (g)+ CO _{2}(g)$

$\because$ Rate of reaction, $\left(\frac{d x}{d t}\right)=k\left[ NO _{2}\right]^{2}$

$\therefore $ Rate is independent of $CO$.

Hence, on adding more $CO$ to the reaction mixture, both $k$ and rate remain the same.