The Rate And Exstent Of Chemical Change

Question 1

Describe rate of a chemical reaction

Answer 1

The speed in which reactants turn into products

Question 2

What are 3 examples of rates of reaction ?

Answer 2

Rusting - more slow

Magnesium in a chemical - takes time but is fast

Fireworks - super quick reaction

Question 3

How do you measure rate of reaction ?

Answer 3

Rate of reaction = quantity of reactants used (divided by) time taken

Question 4

What factors affect rate of reaction ?

Answer 4

Temperature

Concentration participle size

Catalyst

Question 5

what is a catalyst ?

Answer 5

A factor used to speed up rate of reaction

Question 6

Describe the collision theory ?

Answer 6

For particles to react they have to collide with each other with enough sufficient energy (the activation energy)

Question 7

What’s activation energy ?

Answer 7

Activation energy is the energy needed to cause a reaction

Question 8

How does frequency of collisions effect reactions ?

Answer 8

The more Collisions successful means the faster the reaction

Question 9

How does temperature effect rate of reaction ?

Answer 9

The higher the temperature of the reaction means the more energy in the particles which means faster movement and more collisions

This mens more likely to exceed activation energy

Question 10

How does concentration and pressure effect rate of reaction ?

Answer 10

More particles per unit of volume means collisions are more frequent so increases rate of reaction

Question 11

How does surface area increase rate of reaction ?

Answer 11

The higher the surface area means more area covered in the solutions so more frequent collisions resulting in increased rate of reaction

Examples :

Solid block and small chunks of magnesium have surface area in a reaction than a powder as the powder spreads in more area

Question 12

How does a catalyst increase rate of reaction ?

Answer 12

The catalyst lowers activation energy this means they is a higher amount of collisions

Catalysts = substances

Question 13

What is different about a catalyst in a reaction ?

Answer 13

It’s mass is the same as in the start

Lowers activation energy

Not used up in the reaction

Question 14

What does the double arrows mean in a reaction ?

Answer 14

The reaction is reversible

Question 15

What different about the froward and backward reactions ?

Answer 15

They can take part at different rates

Question 16

What is equilibrium ?

Answer 16

When the concentrations of reactants and products won’t change any more

This is because both reactions are taking place at the same time so they cancel each other out

Question 17

What does equilibrium not require ?

Answer 17

The amount of each reactant to be the same only the Rate

Question 18

How do you determine where the equilibrium lies ?

Answer 18

Dependant on the amount of each reactant On each side the equilibrium will be on the side which has most of reactant

Question 19

What’s a factor that must exist for equilibrium ?

Answer 19

Must be within a closed system (apparatus)

Question 20

Why must equilibrium must take place in a closed system ?

Answer 20

So that none of reactants can escape

Question 21

What is different about forward and backwards reactions (reversible reactions) ?

Answer 21

They are exothermic in one direction an endothermic in the other

Question 22

What is Le Chatelier’s Principle ?

Answer 22

In a closed system the reaction will shift to oppose the changes