NEET Solved Paper 2017 Question 43
Question: A first order reaction has a specific reaction rate of $ {10^{-2}}{s^{-1}}. $ How much time will it take for 20 g of the reactant to reduce to 5 g?
Options:
A) 693.0 second
B) 238.6 second
C) 138.6 second
D) 346.5 second
Show Answer
Answer:
Correct Answer: C
Solution:
- $ {{t} _{1/2}}=\frac{0.693}{{10^{-2}}} $ second For the reduction of 20 g of reactant to 5 g, two $ {{t} _{1/2}} $ is required.
$ \therefore $ $ t=2\times \frac{0.693}{{10^{-2}}},seecond $ $ =138.6,second $
