Question

A certain first-order reaction is 27.5 percent complete in 8.90 min at 25°C. What is its rate constant?

Answer 1

Answer:

$k= 0.145min^{-1}$

Explanation:

Hello there!

In this case, according to the given information, it turns out necessary for us remember that the first-order kinetics is given by:

$ln(A/A_0)=-kt$

Whereas the 27.5% complete means A/Ao=0.275, and thus, we solve for the rate constant as follows:

$k=\frac{ln(A/A_0)}{-t}$

Then, we plug in the variables to obtain:

$k=\frac{ln(0.275)}{-8.90min}\\\\k= 0.145min^{-1}$

Regards!