Question

The above reaction is run and found to follow second order kinetics with a rate constant of 1.30 x 10-3 M-1sec-1. If the initial concentration of A is 1.54 M, what is the concentration after 172 seconds?

Answer 1

The final concentration after 172 seconds is 1.15 M. To obtain this answer, use the the integrated rate law for the order of reaction. Based on the problem, this is a second order reaction. The units of the rate constant also support that it is a second order reaction.

Further Explanation:

The solution to this problem is straightforward.

1. Identify the integrated rate law for the corresponding order of reaction.
2. Substitute the given values into the integrated rate law equation.
3. Use algebra to solve for the unknown, C(f).

STEP 1: Since the reaction is a second order reaction, the integrated rate law will be:

$\frac{1}{C_{f}} = \ kt \ + \frac{1}{C_{i}}$

where:

C(f) is the final concentration

k is the rate constant

t is the time

C(i) is the initial concentration

STEP 2: Plugging in the values given in the problem into the equation, the following equation should be obtained:

$\frac{1}{C_{f}} \ = (1.30 \ x \ 10^{-3} \frac{ \ 1 }{ \ M-s})(172 \ s) \ + \ \frac{1}{1.54 \ M}$

STEP 3: Using algebra to solve for C(f):

$\frac{1}{C_{f}} = \ 0.87295\\ \\C_{f} = \ 1.14554 \ M$

Since the given values only have 3 significant figures, the final answer must be expressed with 3 significant figures as well.

Therefore,

$\boxed {C_{f}\ = \ 1.15 \ M}$

Learn More

1. Learn more about half life brainly.com/question/4318844
2. Learn more about first order reaction brainly.com/question/8139015
3. Learn more about rate law brainly.com/question/1450796

Keywords: rate law, second order, integrated rate law