A) 50 min
B) 100 min
C) 99 min
D) 150 min
Correct Answer: C
Solution :
Given, Idea: \[k=\frac{2.303}{t}\log \frac{a}{a-x}\] Given, \[t=15,a=100,a-x=50\] \[\therefore \] \[k=\frac{2.303}{15}\log \frac{100}{50}\] \[k=\frac{2.303}{15}\log \,2\] ?(i) Also \[t=?,a=100,\,a-x=100-99=1\] \[\therefore \] \[k=\frac{2.303}{t}\log \frac{100}{1}\] or \[k=\frac{2.303}{t}\log 100\] ?(ii) From Eqs. (i) and (ii). \[\frac{2.303}{15}\log 2=\frac{2.303}{t}\log 100\] or \[\frac{1}{15}\log 2=\frac{1}{t}\log 100\] or \[\frac{0.3010}{15}=\frac{2}{t}\] or \[t=\frac{15\times 2}{0.3010}\] \[=99\,\min \]You need to login to perform this action.
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