Paper 2:The Rate and Extent of Chemical Change

Question 1

Example of fast and slow reaction

Answer 1

Fast- firework
Slow- Rusting

Question 2

What is rate of reaction

Answer 2

How quickly a product is formed or how quickly a reactant is used up

Question 3

What are successful collisions

Answer 3

When particles collide with enough energy for a chemical reaction to occur

Question 4

Rate of reaction equations

Answer 4

Time

Question 5

How can you measure the rate of reaction using gases

Answer 5

Measuring how much mass is lost in g/s of the reaction

Question 6

How to measure gas

Answer 6

Run all gas into a gas syringe
Run all gas into water and then into a measuring cylinder

Question 7

Which plateaus first a fast or slow reaction

Answer 7

Fast

Question 8

Which factors affect the rate of reaction

Answer 8

Concentration
Pressure
Temperature
Catalyst
Surface area

Question 9

What do catalyst do

Answer 9

Increase the rate of reaction by decreasing activation energy

Question 10

How do catalysts work

Answer 10

Increase the rate of successful collisions as more particles have energy that is more than the activation energy

Question 11

How does increasing pressure/ concentration work

Answer 11

More frequent successful collisons

Question 12

How does increasing temperature work

Answer 12

The particles have more kinetic energy so move faster and have more frequent collisions

Question 13

How does increasing surface area work

Answer 13

More area of the substance is exposed to the reactant particles more frequent collisions

Question 14

How do you workout the rate of reaction at any point on a map

Answer 14

Workout gradient

Question 15

When can dynamic equilibrium occur

Answer 15

Closed system
Reversible reaction

Question 15

What is dynamic equilibrium

Answer 15

The forward and backwards reversible reactions occur at the same rate
Concentrations stay the same

Question 16

What is the Haber process

Answer 16

Reacting Nitrogen and hydrogen to produce ammonia

Question 17

What is Le Chatelier’s principle

Answer 17

The equilibrium of a reversible reaction can be changed by the conditions

Question 17

What does the Haber process require

Answer 17

450C and 200a
Iron catalyst

Question 18

What will increasing the temperature in the reversible reaction do?

Answer 18

Equilibrium goes to endothermic

Question 19

What will increasing the pressure in the reversible reaction do?

Answer 19

It goes towards the sides with less molecules (moles)

Question 20

What will increasing the concentration of the reactant do

Answer 20

Equilibrium goes to products

Question 21

What will increasing the concentration of the product do

Answer 21

Equilibrium goes to products

Question 22

What is a reversible reaction

Answer 22

Where the reactants can react to form the products and vise versa

Question 23

Copper sulfate reversible reaction

Answer 23

hydrated copper sulfate —> anhydrous copper sulfate plus water

Question 24

How to measure amount of gas produced required practical calcium carbonate with hydrochloric acid

Practical for different concentrations

Answer 24

Gas syringe is clamped to a retort stand with delivery tube connected to it and conical flask
50ml of HCl measured into measuring cylinder then flask
Use balance to measure 0.5g of powdered calcium carbonate and add to conical flask
Put bung and delivery tube on conical flask
Record volume of carbon dioxide produced every 10 seconds
Do this for different concentrations and workout means and compare

Question 25

Time for cross to disappear required practical with different temperatures of sodium thiosulfate

Answer 25

Black cross on white tile
35cm3 of sodium thiosulfate using a measuring cylinder
5 cm3 of water and 10cm3 of HCl in seperate measuring cylinders
Pour water and acid into conical flask
Pour sodium thiosulfate into conical flask and start stopwatch
Stop stopwatch when cross is not visible
Repeat with different temperatures of Sodium Thiosulfate