NEET Chemistry Chemical Kinetics Questions Solved


For a first-order reaction, the time required for 99.9% of the reaction to take place is nearly :

(1) 10 times that required for half of the reaction

(2) 100 times that required for two-third of the reaction

(3) 10 times that required for one-fourth of the reaction

(4) 20 times that required for half of the reaction

(1) t99.9 = (2.303/k)log (100/100-99.9) = 6.909/k ....(1)

     Now, t1/2 = (2.303/k)log (100/100-50) = (2.303/k)log2 ....(2) 

     From (1) and (2) 

     t99.9 / t1/2 =10

Difficulty Level:

  • 60%
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  • 22%
  • 6%