1)

For  the elementary reaction M→ N,  the rate of disappearance of M increases by  a factor of 8 upon doubling   the concentration of M. The order of the reaction with respect to M is


A) 4

B) 3

C) 2

D) 1

Answer:

Option B

Explanation:

For the elementary reaction, M→N

 Rate law can be written as

          Rate   [M]n

   Rate = k[M]n       ...........(i)

 When we double the concentration of  [M]  , rate becomes  8 times , hence  new rate law can be written as

       8×Rate=k[2M]n        ...........(ii)

   Rate8×Rate=k[M]nk[2M]n

    

     18=1[2]n[2]n=8=[2]3

           n=3

 Hence, (b) is the correct choice.