The Rate And Extent Of Chemical Change

Question 1

What is the formula for rate of reaction

Answer 1

Amount of product or reactant / time taken

Question 2

What five factors can affect rate of reaction

Answer 2

Concentration
Surface area
Pressure
Catalyst
Temperature

Question 3

What is the definition of a catalyst

Answer 3

A substance that increases the rate of reaction without being changed or used up by the reaction itself

Question 4

How does a catalyst work (1 mark)

Answer 4

Provides an alternative reaction pathway with a lower activation energy

Question 5

Explain the affect of a catalyst on the rate of reaction (4)

Answer 5

Decrease activation energy
So more particles have energy over activation energy
So more frequently successful particles collisions
Increase in rate of reaction

Question 6

How do ……. Affect rate of reaction (4)
Pressure
Concentration
Surface area

Answer 6

Increase in ….. (pressure, concentration, surface area)
Increase in number of particles in a given area
So more frequent successful collisions between particles
So increase rate of reactions

Question 7

What is collision theory

Answer 7

Chemical reactions can only occur when enough particles have collided with each other with enough energy

Question 8

Define activation energy

Answer 8

The minimum amount of energy required for a reaction to take place

Question 9

What is a reversible reaction

Answer 9

Where the products of a reaction can react to produce the reactants

Question 10

Define equilibrium

Answer 10

When both the forwards and backwards reactions occur at the same rate
Occurs in a closed system

Question 11

What’s le chatelier’s principle

Answer 11

If a change is made to a system while it’s at equilibrium the system will respond with an equal and opposite reaction

Question 12

Explain the effect of an increase in concentration of reactants on a system at equilibrium

Answer 12

Equilibrium shifts to the products side
Increase in yield of products

Question 13

Explain the effect of a decrease in concentration of reactants of a system while at equilibrium

Answer 13

Equilibrium shifts to the reactants side
Increase in yield of reactants

Question 14

Explain the effect of an increase in concentration of products in a system at equilibrium

Answer 14

Equilibrium shifts to the reactants side
Increase in yield of reactants

Question 15

Explain the effect of decrease in concentration of products in a system at equilibrium

Answer 15

Equilibrium shifts to the products side
Increase in yield of products

Question 16

Explain the effect of an increase in temperature in a system at equilibrium

Answer 16

Equilibrium shifts to the endothermic side
So increase in yield of whatever is in that side

Question 17

Explain the effect of a decrease in temperature of a system at equilibrium

Answer 17

Equilibrium shifts to the exothermic side
Increase in yield of whatever’s on that side

Question 18

Explain the effects of increase in pressure of a system at equilibrium

Answer 18

Equilibrium shifts to the less moles side
Increase in yield of whatever’s on that side

Question 19

Explain the effect of decrease in pressure of a system at equilibrium

Answer 19

Equilibrium shifts to the more moles side
Increase in yield of whenever is on that side