NTA Abhyas NEET2020ChemistryChemical KineticsPractice
For a reactions A + B → product, it was found that rate of reaction increases four times if concentration of ' A ' is doubled. But the rate of reaction remains unaffected, if concentration of ' B ' is doubled. Hence, the rate law for the reaction is
Options
- Ar a t e = k [ A ] [ B ]
- Br a t e = k [ A ] 2
- Cr a t e = k [ A ] 2 [ B ] 1
- Dr a t e = k [ A ] 2 [ B ] 2
Correct answer
B. r a t e = k [ A ] 2
Step-by-step solution
Let the rate of reaction depends on x t h power of [ A ] . Then r 1 = k [ A ] x and r 2 = k [ 2 A ] x ∴ r 1 r 2 = [ A ] x [ 2 A ] x = 1 4 = 1 2 2 ( ∵ r 2 = 4 r 1 ) ∴ x = 2 . As the reaction rate does not depend upon the concentration of B. Hence, the correct rate law will be r a t e = K [ A ] 2 [ B ] o or = K [ A ] 2