Chemistry Paper 2

Question 1

What does rate of reaction mean?

Answer 1

How fast a chemical reaction takes place.

Question 2

How can you measure the rate of a reaction?

Answer 2

Measure how quickly reactants are used up or products are formed.

Question 3

Name three ways to measure rate of reaction.

Answer 3

Change in mass, volume of gas produced, or how quickly a solution becomes cloudy.

Question 4

What are the main factors that affect rate of reaction?

Answer 4

Temperature, concentration, surface area, and catalysts.

Question 5

How does temperature affect rate?

Answer 5

Higher temperature = faster particles = more frequent successful collisions.

Question 6

How does concentration affect rate?

Answer 6

Higher concentration = more particles = more collisions.

Question 7

How does surface area affect rate?

Answer 7

More surface area = more area for particles to collide = faster rate.

Question 8

What is a catalyst?

Answer 8

A substance that speeds up a reaction without being used up.

Question 9

What is crude oil?

Answer 9

A mixture of hydrocarbons formed from ancient biomass.

Question 10

What are hydrocarbons made of?

Answer 10

Hydrogen and carbon only.

Question 11

What are alkanes?

Answer 11

Saturated hydrocarbons with the formula CnH2n+2.

Question 12

Name four alkanes.

Answer 12

Methane, ethane, propane, butane.

Question 13

What are the properties of short-chain hydrocarbons?

Answer 13

Lower boiling points, more flammable, flow easily.

Question 14

What are the properties of long-chain hydrocarbons?

Answer 14

Higher boiling points, less flammable, thicker.

Question 15

What is fractional distillation?

Answer 15

Separating crude oil into fractions based on boiling points.

Question 16

What is cracking?

Answer 16

Breaking long-chain hydrocarbons into shorter alkanes and alkenes.

Question 17

Why is cracking useful?

Answer 17

Produces more useful fuels and raw materials for plastics.

Question 18

What is a pure substance in chemistry?

Answer 18

A substance with only one type of element or compound.

Question 19

How can you tell if a substance is pure?

Answer 19

It has a fixed melting and boiling point.

Question 20

What is a formulation?

Answer 20

A mixture made with exact amounts for a specific purpose.

Question 21

Give examples of formulations.

Answer 21

Medicines, paints, fuels, cosmetics.

Question 22

What is chromatography used for?

Answer 22

To separate mixtures like inks and dyes.

Question 23

What does an Rf value show?

Answer 23

How far a substance travels compared to the solvent.

Question 24

What was Earth’s early atmosphere like?

Answer 24

Mostly carbon dioxide, little or no oxygen, volcanic gases.

Question 25

How did oxygen increase in the atmosphere?

Answer 25

Plants evolved and released oxygen through photosynthesis.

Question 26

How did carbon dioxide levels decrease?

Answer 26

Photosynthesis, dissolving in oceans, forming fossil fuels and sediments.

Question 27

What are the main greenhouse gases?

Answer 27

Carbon dioxide, methane, and water vapour.

Question 28

What is the greenhouse effect?

Answer 28

Trapping of heat by gases in the atmosphere.

Question 29

What are the effects of global warming?

Answer 29

Climate change, sea level rise, extreme weather.

Question 30

What pollutants are released by burning fossil fuels?

Answer 30

Carbon monoxide, sulfur dioxide, nitrogen oxides, particulates.

Question 31

What problems does carbon monoxide cause?

Answer 31

It's toxic and prevents oxygen transport in blood.

Question 32

What is acid rain caused by?

Answer 32

Sulfur dioxide and nitrogen oxides reacting with water.

Question 33

What are particulates?

Answer 33

Tiny solid particles that cause breathing problems and global dimming.

Question 34

What is a finite resource?

Answer 34

A resource that will eventually run out (e.g. crude oil, metals).

Question 35

What is a renewable resource?

Answer 35

A resource that is naturally replaced (e.g. wood, crops).

Question 36

What is potable water?

Answer 36

Water that is safe to drink.

Question 37

How is potable water produced in the UK?

Answer 37

Filtration to remove solids, then sterilisation (chlorine/UV/ozone).

Question 38

How is water treated in sewage treatment?

Answer 38

Screening, sedimentation, digestion by bacteria, and chemical treatment.

Question 39

Why is recycling important?

Answer 39

Saves energy, raw materials, and reduces pollution.

Question 40

What is a Life Cycle Assessment (LCA)?

Answer 40

A study of the environmental impact of a product from start to finish.