Atoms And Nuclei Question 398

Question: In a certain hypothetical radioactive decay process, species A decays into species B and species B decays into species C according to the reactions: A2B+particles+energy B3C+particles+energy The decay constant for species is λ1=1sec1 and that for the species B is λ2=100sec1. Initially 104 moles of species of A were present while there was none of B and C. It was found that species B reaches its maximum number of moles of B.

Options:

A) 1

B) 2

C) 5

D) 4

Show Answer

Answer:

Correct Answer: B

Solution:

  • dNAdt=λ1NA,,dNBdt=2λ1NAλ2NB, NB= maximum
    dNBdt=0
    2λ1NA=λ2NBmaxNBmax=2λ1λ2NA
    NBmax=2λ1λ2N0eλ1t=2


NCERT Chapter Video Solution

Dual Pane