3.2.2 Reaction rates

Question 1

What do the particles need for a reaction to occur?

Answer 1

To collide

Correct orientation

Minimum amount of energy to react is called the activation energy

Question 2

How does an increase in temperature cause an increase in rate of reaction?

Answer 2

Increase in temp
Particles have more energy
More frequently collisions
More of these collisions are over the activation energy
So rate of reaction increases

Question 3

How does an increase in concentration increase rate of reaction?

Answer 3

Increase in concentration
More particles in the same volume
More particles with greater than the activation energy
More frequent collisions
Rate of reaction increases

Question 4

How do you calculate rate of reaction from a straight line?

Answer 4

1. Make a triangle with the line
2. Workout the change in the Y axis
3. Workout the change in the X axis
4. Workout the gradient (the rate) change in y over the change in x

Question 5

How do you calculate the rate of reaction from a curved line?

Answer 5

1. Find the point on the curve e.g. at 50 seconds
2. Draw a tangent that touches that point and make a triangle
3. Find the change in y
4. Find the change in x
5. Change in y over the change in x

Question 6

What is initial rate and how do you work it out?

Answer 6

Initial rate is calculated by using the beginning of the line starting t=0 to calculate the rate

Question 7

How do you calculate the initial rate from a graph?

Answer 7

1. Draw a straight line at t=0
2. Workout change in y
3. Workout change in x
4. Change in y over change in x