Question

t(min) [A](M)

21.0 1.260

124.0 9.700X10-1

385.0 4.995X10-1

673.0 2.401X10-1

922.0 1.275X10-1

a.) What is the order of the reaction with the above data?


b.) Calculate the k for the reaction.


c.) Calculate the original concentration of A for the reaction.


d.) Assuming the original concentration in part (c) calculate the half-life of the reaction.

Answer 1

Solution.

1.

This figure shows graphs of concentration-time dependencies for 0, 1, 2, and 3 reaction orders. As we can see, a linear dependence of order 1 is observed for these values.

2.

$k = \frac{1}{t} \times ln(\frac{C0}{C})$

k = 0.0025

3.

$C0 = e^{kt} \times C$

$C0 = e^{0.0025 \times 21} \times 1.26 = 1.33 \ M$

4.

$t(1/2) = \frac{ln(2)}{k}$

t(1/2) = 277.26 min

Answer:

1.

1 order

2.

k = 0.0025

3.

1.33 M

4.

t(1/2) = 277.26 min