Question

The rate of first order reaction, $A\to$ Products, is $7.5$ M/s. If the concentration of $A$ is 0.5 M. The rate constant is:

• A. 3.75
• B. 2.51
• C. 15.0
• D. 8.01

Answer 1

Answer: (C)

15.0

As we know that,

$r\left(rate\right)=K\left[A\right]$ ------ 1

where,

$r=$ Rate of reaction $=7.5mol/(L.s)$

$K=$ Rate constant $=?$

$\left[A\right]=$ Initial concentration of reactant $=0.5mol/L$

Therefore,

$K=\frac{7.5}{0.5}=15.0s^{-1}$

Hence the rate constant for the given reaction is $15.0s^{-1}$.