Rate Of Reaction

Question 1

What does the gradient of a graph showing the rate of reaction represent

Answer 1

The rate of reaction

Question 2

When the gradient is zero what does that tell about the reaction

Answer 2

The reaction has stopped as all the reactants are used up

Question 3

How do you calculate the mean rate of reaction

Answer 3

Quantity of product formed / Time taken

Question 4

How do you calculate the rate of reaction at a given point

Answer 4

By drawing a tangent at the specific point

Question 5

How do you calculate the gradient (h)

Answer 5

Change in Y / Change in X

Question 6

What is collision theory

Answer 6

Chemical reactions can only take place when the reacting particles collide with each other, the collisions must have sufficient energy

Question 7

What is the rate of reaction determined by

Answer 7

The frequency of successful collisions

Question 8

What does increasing the concentration do to the rate of reaction

Answer 8

It increases the rate of reaction because there are more particles to react with

Question 9

What’s the relationship between the rate of reaction and concentration

Answer 9

The rate is proportional to the concentration

Question 10

What is meant by the term frequency

Answer 10

The number of successful collisions per second

Question 11

What part of the solid can particles react with

Answer 11

The surface of the solid

Question 12

What’s the effect of increasing the surface area on the rate of reaction

Answer 12

It increases the number of collisions per second so the rate of reaction increases

Question 13

How do you increase the surface area to volume ratio

Answer 13

By decreasing the size of the solids

Question 14

What is required for there to be a successful collision

Answer 14

When collisions overcome the activation energy

Question 15

What does increasing the temperature do to the rate of reaction

Answer 15

Increase the rate of reaction

Question 16

Explain why increasing the temperature increases the rate of reaction

Answer 16

The particles have more energy so the frequency of collisions increases because more particles can overcome the activation energy barrier and collide successfully

Question 17

What is the relationship between the rate of reaction and temperature

Answer 17

They are proportional

Question 18

What is the role of catalysts

Answer 18

They increase the rate of reaction but aren’t used up during the reaction

Question 19

Why do catalysts increase the rate of reaction

Answer 19

Because they lower the activation energy by offering an alternative pathway for the particles

Question 20

What are reversible reactions

Answer 20

When products can react to reform the original reactants

Question 21

If a reversible reaction is exothermic in one direction what is it in the opposite direction

Answer 21

Endothermic

Question 22

What is equilibrium

Answer 22

The point where the forward and reverse reactions take place at exactly the same rate

Question 23

What is Le Chatliers principal

Answer 23

If a system is at equilibrium and a change is made to the conditions then the system responds to counteract the change

Question 24

What happens when you increase the temperature of reversible reaction

Answer 24

The equilibrium shift to reduce the temperature

Question 25

What does the pressure of a gas depend on

Answer 25

The number of molecules

Question 26

What happens if the pressure increases on a reversible reaction at equilibrium

Answer 26

The position of the equilibrium shift to the side of the smaller number of molecules