Chemistry paper 2

Question 1

Give the definition for a fuel.

Answer 1

Substances that release energy when burned.

Question 2

Describe the composition of a hydrocarbon.

Answer 2

Chemicals made from carbon and hydrogen atoms only.

Question 3

List the properties of short chain hydrocarbons?

Answer 3

Low boiling points; High volatility; Low viscosity; High flammability.

Question 4

List the properties of long chain hydrocarbons.

Answer 4

High boiling points; Low volatility; High viscosity; Low flammability.

Question 5

List the properties of alkanes.

Answer 5

Names end in ane; No double bonds; Saturated; General formula: CnH2n+2

Question 6

List the first 5 alkanes.

Answer 6

Methane, ethane, propane, butane, pentane

Question 7

List the properties of alkenes.

Answer 7

Names end in ene; Double bonds between carbon atoms; Unsaturated; General formula: CnH2n

Question 8

List the first 5 alkenes.

Answer 8

Ethene, propene, butene, pentene, hexene

Question 9

Define complete combustion.

Answer 9

Burning a fuel in a good supply of oxygen.

Question 10

Give the word equation for complete combustion

Answer 10

Fuel + oxygen → Carbon dioxide + water

Question 11

Define incomplete combustion.

Answer 11

Burning a fuel in a limited supply of oxygen.

Question 12

Give the word equation for incomplete combustion.

Answer 12

Fuel + oxygen → carbon monoxide + carbon + water

Question 13

Describe the properties of carbon monoxide.

Answer 13

Colourless, odourless gas.

Question 14

Describe the effects of carbon monoxide.

Answer 14

Stops red blood cells carrying oxygen. Causes dizziness, nausea, brain damage and death.

Question 15

Describe the composition of crude oil.

Answer 15

A mixture made from many different hydrocarbons.

Question 16

Name the process used to separate the hydrocarbons in crude oil.

Answer 16

Fractional distillation

Question 17

Describe the process of cracking.

Answer 17

Breaking large un-useful hydrocarbons into smaller more useful ones.

Question 18

List the conditions needed for cracking.

Answer 18

A catalyst, steam.

Question 19

Give the chemical used to test for hydrocarbons.

Answer 19

Using bromine water, which is orange.

Question 20

Describe the colour bromine water will turn in an alkene.

Answer 20

Colourless

Question 21

Describe the colour bromine water will turn in an alkane.

Answer 21

No change. Stays orange.

Question 22

Give the equations for calculating the rate of reaction

Answer 22

Reactant used / time; Product formed / time

Question 23

Describe collision theory

Answer 23

Particles must collide with enough energy in order for a reaction to occur.

Question 24

Define activation energy

Answer 24

Minimum energy required for a reaction to occur.

Question 25

Name 5 factors that affect the rate of reaction

Answer 25

Catalysts, temperature, surface area, concentration, pressure.

Question 26

Explain how catalysts speed up a chemical reaction

Answer 26

Using a catalyst = faster reaction.; Provides a different pathway with a lower activation energy.

Question 27

Explain how temperature speeds up a chemical reaction

Answer 27

Higher temperature = faster reaction.; Particles have more kinetic energy.; More successful collisions per second.

Question 28

Explain how surface area speeds up a chemical reaction

Answer 28

Large surface area = faster reaction.; Chances of particles colliding increases.; More successful collisions per second.

Question 29

Explain how concentration speeds up a chemical reaction

Answer 29

Higher concentration = faster reaction.; Less space for particles to move without colliding.; More successful collisions per second.

Question 30

Explain how pressure speeds up a chemical reaction

Answer 30

Higher pressure = faster reaction.; Less space for particles to move without colliding.; More successful collisions per second.

Question 31

Explain why catalysts are useful

Answer 31

Can be reused.; They save fuel, time and money.; Reduce the need for high temperatures.; Reduce pollution.

Question 32

Define a reversible reaction

Answer 32

Reactions where products can reform reactants.

Question 33

Define dynamic equilibrium

Answer 33

When the forwards and backwards reactions happen at the same rate.