Chemistry In Everyday Life Ques 5
5. Which one of the following is employed as a tranquilizer?
[2009]
(a) Naproxen
(b) Tetracycline
(c) Chlorpheninamine
(d) Equanil
Show Answer
Answer:
Correct Answer: 5.(c)
Solution:
(c) As we know that
$ \frac{N}{N_0} = (\frac{1}{2})^n $
Where $N_0$ original amount of radioactive sustaence
N = Amount of substance remain after n half lives
$ \therefore \frac{25}{200} = (\frac{1}{2})^n$ or $\frac{1}{8} = (\frac{1}{2})^n $
or, $ \hspace{3mm} (\frac{1}{3})^n = (\frac{1}{2})^n : \therefore n = 3 $
now $T=n \times t _{1/2}$
where T = total time
$T=3 \times 5760 $ years = 17280 years
BETA
