4.1 Kinetics

Question 1

Give the most basic example of a rate equation using X and Y

Answer 1

Rate = k [x][y]

Question 2

rate = k [x][y]^2

What are the orders for X and Y

Answer 2

X is first order and Y is second order

Question 3

When using first order values and you increase the value by X, how much does the rate increase by?

Answer 3

X^1

Question 4

When using second order values and you increase the value by X, how much does the rate increase by?

Answer 4

X^2

Question 5

What is the unit used for the values?

Answer 5

Mol/dm3

However it is possible to have no units if the units on the top and bottom of the equation cancel each other out.

Question 6

How is a 0 order value shown in a rate equation?

Answer 6

It isn’t. Anything that is 0 order is that value to the power of 0 meaning it is just 1 and so it doesn’t feature in the rate equation

Question 7

Why does a change in temperature affect the rate equation?

Answer 7

Because it will increase or decrease the number of molecules with energy at or above the activation energy, and therefore affect the number of successful collisions.

Question 8

What will happen if the temperature is increased without altering the concentration of a variable?

Answer 8

The value of k will increase because the rate increases when the temperature increases.

Question 9

What is a rate determining step.

Answer 9

The slowest step in a reaction. The reaction cannot go faster than its slowest stage, this is the rate determining step.

Question 10

What does the rate equation tell us?

Answer 10

The contributions of the species that affect the reaction rate.