# 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%
• 14%
• 22%
• 6%