C8 - Rates and equilibrium 2️⃣✅

Question 1

What is dynamic equilibrium?

Answer 1

A point where both reactions are taking place at the same time so it looks like there is no change/ are happening at the exact same rate and will follow La Chatelier’s principle to change/ move to reistablish equilibrium

Question 2

What is La Chatelier’s Principle?

Answer 2

That a sysytem will do the opposite in order to reistablish equilibrium

Question 3

What is the rate of reaction?

Answer 3

The measure of the speed at which something happens in a given time

Question 4

What are the 4 things that can affect the rate of reaction?

Answer 4

• Presence of a catalyst
• Temperature
• Concentration & pressure
• Surface area of solids

Question 5

How do catalysts affect the rate of a reaction?

Answer 5

Catalysts work by providing alternate reaction pathways to the products with a lower activiation energy than without the catalysts present to increase the rate of reaction

Question 6

How does temperature affect the rate of a reaction?

Answer 6

By heating up a substance more kinetic energy is generated and therefore particles move around faster and therefore collide much more frequently. When particles collide more frequently there is an increased chance they will react, therefore increasing the rate of reaction

Question 7

How does concentration & pressure affect the rate of a reaction?

Answer 7

By increasing the pressure, there is less space avainable for particles to move therefore increasing the frequency of collisions and therefore increases rate of reaction. Increasing the concentration of reactants causes more frequent collisions and therefore increases rate of reaction.

Question 8

How does surface area of a solid affect the rate of a reaction?

Answer 8

Only reactant particles are capable of colliding and reacting, therefore by increasing the surface area you are increasing the number of reactant particles exposed, leading to more frequent collisions and therefore increasing rate of reaction

Question 9

What is collision theory?

Answer 9

The idea that in order for a reaction to occur paricles must collide, and that in order for particles to react when they collide they must surpass the activation energy - minimunm ammount of energy for a collision to be sucsesful/ to collide and therefore react

Question 10

If a reaction is exothermic in one direction….

Answer 10

it will be endothermic in the other

Question 11

What is a reversable reaction?

Answer 11

When a reactions reactants can turn into products and the products can turn into the reactants

Question 12

What is the equation for the mean rate of reaction?

Answer 12

Question 13

What does hydrous mean?

Answer 13

That something contains water

Question 14

What does anhydrous mean?

Answer 14

That something does not contain water

Question 15

If the concentration of a reactant is increased, ________ products will be formed until equilibrium is reached again.

Answer 15

If the concentration of a reactant is increased, more products will be
formed until equilibrium is reached again.

Question 16

If the concentration of a product is decreased, ________ reactants will react until equilibrium is reached again.

Answer 16

If the concentration of a product is decreased, less reactants will react until equilibrium is reached again.

Question 17

If the temperature of a system at equilibrium is increased what will happen?

Answer 17

• Endothermic reaction direction is favoured
• The ammount of products increases for an endothermic reaction
• The ammount of products decreases for an exothermic reaction

Question 18

If the temperature of a system at equilibrium is decreased what will happen?

Answer 18

• Exothermic reaction direction is favoured
• The ammount of products decreases for an endothermic reaction
• The ammoun of products increases for an exothermic reaction

Question 19

If the pressure of a system at equilibrium is increased what will happen?

Answer 19

• Favour direction/side with the fewest number of molocules
• An increase in pressure causes the equilibrium position to shift towards (favour) the side with the smaller number of molecules as shown by the symbol equation for that reaction

Question 20

If the pressure of a system at equilibrium is decreased what will happen?

Answer 20

• Favour direction/side with the largest number of molocules
• An decrease in pressure causes the equilibrium position to shift towards (favour) the side with the larger number of molecules as shown by the symbol equation for that reaction

Question 21

What is equilibrium?

Answer 21

When, in a reversible reaction the forward and reverse reactions occur at exactly the same rate/ are taking place at the same time so it looks like there is no change/ are happening at the exact same rate

Question 22

What is the activation energy?

Answer 22

The minimum ammount of energy that particles must have to react

Question 23

What does turbidity mean?

Answer 23

the quality of a substance/ solvent being cloudy/ opaque

Question 24

Give 4 ways of measuring the rate of a reaction

Answer 24

• Measuring loss of mass
• Volume of gass produced
• Colour Change
• Turbidity of a reaction mixture