Chapter 18: Kinetics

Question 1

How do you calculate the rate of reaction at any instant on a concentration time graph?

Answer 1

Draw a tangent to the curve at the point at which you wish to find the rate of reaction and calculate its gradient, (dy/dx).

Question 2

What does the rate expression tell us?

Answer 2

The contribution of the species of the species that do affect the reaction rate.

Question 3

Whats the only way to find out which species contributes to the rate of reaction and therefore work out the rate expression?

Answer 3

By experiment.

Question 4

What affect on the rate of reaction would happen if you were to double the concentration of each species, which had a rate expression of: rate is dp to [X][Y]^2

Answer 4

Double [X] would doublle rate.

Double [Y] would quadruple rate.

Question 5

Rearrange: rate = k[X][Y]^2 in respect to k and give the units of k

Answer 5

k = rate/[X][Y]^2

units: mol^-2dm^6s^-1

Question 6

What is the order of each species of the reaction:

X+Y+2Z -> A

With the rate expression: rate =k[X][Y]^2

Answer 6

X - order 1

Y -order 2

Z - order 0