Question

In the first order reaction, half of the reaction is complete in 100 seconds. The time for 99% of the reaction to occurs will be

Options

• 712.605

• 666.64

• 321.455

• 281.625

Answer 1

666.64

Explanation:

K = `0.693/100 S^-1` 

t(99.9%) = `2.303/K  log  a/((a - x))`

= `(2.303 xx 1005)/0.693 xx log  100/1`

= `(2303 xx 100 xx 2)/0.693`

= 666.645