Question

The reaction, $X⟶Y$ (Product), follows first order kinetics. In $40$ minutes, the concentration of $X$ changes from $0.1$ $M$ to $0.025$ $M$, then the rate of reaction when concentration of $X$ is $0.01$ $M$ is:

• A. $1.73\times {10}^{-4}M/min$
• B. $3.47\times {10}^{-5}M/min$
• C. $3.47\times {10}^{-4}M/min$
• D. $1.73\times {10}^{-5}M/min$

Answer 1

Answer: (C)

$3.47\times {10}^{-4}M/min$

$\ln \left(\frac{0.1}{0.025}\right)=ktk=\frac{\ln \left(4\right)}{40}SoforA=0.01MThus,Rate=k\left[A\right]=\frac{\ln \left(4\right)}{40}\left(0.01\right)=3.47\times {10}^{-4}M/min$