Question

The half-life of radioisotopic bromine - 82 is 36 hours. The fraction which remains after one day is _____ \(\times 10^{-2}.\)

(Given antilog 0.2006 = 1.587)

Answer 1

Correct answer is : 63

Half life of bromine – 82 = 36 hours

\(t_{1/2}=\frac {0.693}{K}\)

\(K = \frac {0.693}{36} = 0.01925\,hr^{-1}\)

1^st order rxn kinetic equation

If a = 1

\(\frac {1}{1-x}= 1.587\) ⇒ 1 - x = 0.6301 = Fraction remain after one day