Question

Consider the following first-order reaction: A → B. The concentration of A at the start of the reaction is 4.17 M and after 4.84 s is 3.56 M. (a) Using the integrated rate law for a first-order reaction, calculate the value of the rate constant.

Answer 1

Answer : The value of rate constant is,
`0.0327s^(-1)`

Explanation :

First we have to calculate the rate constant, we use the formula :

Expression for rate law for first order kinetics is given by:

`k=(2.303)/(t)\log(a)/(a-x)`

where,

k = rate constant = ?

t = time passed by the sample = 4.84 s

a = initial concentration = 4.17 M

a - x = concentration after time 4.84 s = 3.56 M

Now put all the given values in above equation, we get

`k=(2.303)/(4.84)\log(4.17)/(3.56)`

`k=0.0327s^(-1)`

Therefore, the value of rate constant is,
`0.0327s^(-1)`