Question

In the reaction, $2NO+C{l}_2\to 2NOCl$, it has been found that doubling the concentration of both the reactants increases the rate by a factor of eight but doubling the chlorine concentration alone only doubles the rate. Which of the following statements is incorrect?

• A. The reaction is first order in $C{l}_2$
• B. The reaction is second order in $NO$
• C. The overall order of reaction is $2$
• D. The overall order of reaction is $3$

Answer 1

The correct option is C The overall order of reaction is $2$

Let the rate of the reaction be given by

rate=$k\left[NO{]}^x\right[C{l}_2{]}^y$

By given conditions, 8x rate=$k\left[2NO{]}^x\right[2C{l}_2{]}^y$

$8=26x+y$ or x+y=3

Also, 2x rate=$k\left[NO{]}^x\right[2C{l}_2{]}^y$

$2=2^y$ or $y=1$

x=2

rate=$k\left[NO{]}^2\right[C{l}_2]$

Overall order=3