Home
Class 12
CHEMISTRY
It is observed that only 0.39% of the or...

It is observed that only 0.39% of the original radioactive sample remains undecayed after eight hours.Hence:

A

the half of that substance is 1hr

B

the mean life of the substance is `1/(log_(e)2)` hr

C

decay constant of the substance is `(log_(e)2)"hour"^(-1)`

D

if the number of radioactive nuclei of this substance at a given instant is `10^(8)` then the number left after 30 min would be `sqrt(2)xx10^(9)`

Text Solution

Verified by Experts

The correct Answer is:
A, B, C
`0.693/(t_(1/2))xx8=2.303xxlog(100/0.39),t_(1/2)~=1,lamda=0.693=1_(n)2,tau=1/(lamda)=(1/(1_(n)2))`
`(2.303xxlog^(2))xx1/2=2.303xxlog((10^(8))/(N_(t))),N_(t)=(1/(sqrt(2))xx10^(8))`
Promotional Banner

Topper's Solved these Questions

  • CHEMICAL KINETICS

    AAKASH SERIES|Exercise PRACTICE SHEET-4 (LINKED COMPREHENSION TYPE QUESTIONS)|6 Videos

  • CHEMICAL KINETICS

    AAKASH SERIES|Exercise PRACTICE SHEET-4 (MATCH THE FOLLOWING QUESTIONS)|2 Videos

  • CHEMICAL KINETICS

    AAKASH SERIES|Exercise PRACTICE SHEET-3 (INTEGER ANSWER TYPE QUESTIONS)|6 Videos

  • CHEMICAL KINETCS

    AAKASH SERIES|Exercise EXERCISE - 3.2|45 Videos

  • CHEMICAL THERMODYNAMICS

    AAKASH SERIES|Exercise Additional Practice Exercise|54 Videos

Similar Questions

Explore conceptually related problems

In a sample of a radioactive substance what fraction of the initial number of nuclei will remain undecayed after a time t =T/2 where T=half-life of radioactive substance.

The half life of a radioactive isotope is 2.5 hour . The mass of it that remains undecayed after 10 hour is (If the mass of the isotope was 16 g) :

Tritium has a half-life of 12.5 y undergoing beta decay. What fraction of sample of pure tritium will remain undecayed after 25 y.

Consider a radioactive nuclide which follow decay rate given by A (t) = A_(0)2^(-(l//t_(0))), where A (f) is the fraction of radioactive material remaining after time t from the initial A_(0) at zero time. Let A_(1) be the fraction of orginal activity which remains after 120 hours. likewise A_(2) is the fraction of 200 hours. If (A_(1))/(A_(2))= 1.6, then the half-life (t_(0)) will be

Sucrose decompose in acid solution into glucose and fructose according to the first order rate law, with t_(1/2)=3.00 hours. What fraction of sample of sucrose remains after 8 hours ?