Q. The time for half-life period of a creation reaction $A \rightarrow$products is 1 h. when the initial concentration of the reactant ‘A’, is $2.0\ mo{l\ L}^{- 1}$, how much time does it take for its concentration to come from 0.50 to $0.25\ mol\ L^{- 1}$, if it is a zero order reaction?
A) 4 h
B) 0.5 h
C) 0.25 h
D) 1 h
Explanation
(c)
For a zero order reaction
$k_{0} = \frac{\lbrack A_{0}\rbrack}{2t_{1/2}}$
Since,$\lbrack A\rbrack_{0} = 2\ M,t_{1/2} = 1\ h$
So, $k_{0} = 1\$and
$k_{0} = \frac{\mathrm{\Delta}x}{t}\ or\ t = \frac{0.50 - 0.25}{1} = 0.25\ h$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.