organics 1

Question 1

what is crude oil

Answer 1

a mixture of hydrocarbons

Question 2

what is a hydrocarbon

Answer 2

a compound containing only hydrogen and carbon

Question 3

what happens to the boiling point if the chain is longer and why

Answer 3

longer chain = higher boiling point
this is because a longer chain has more IMF’s so more energy is needed to overcome all the forces

Question 4

what happens to the boiling point if the chain is shorter and why

Answer 4

shorter chain = lower boiling point
this is because a shorter chain has less IMF’s so less energy is needed to overcome all the forces.

Question 5

how do we separate crude oil?

Answer 5

fractional distillation

Question 6

what is the name of the fraction of crude oil with the lowest boiling point and is also the smallest molecule?

Answer 6

refinery gas

Question 7

what is the name of the fraction with the highest boiling point which also contains the largest molecules?

Answer 7

bitumen

Question 8

name each fraction in order

Answer 8

refinery gas
gasoline
kerosene
diesel
fuel oil
bitumen

Question 9

what is the use of refinery gas

Answer 9

home heating

Question 10

what is the use of gasoline

Answer 10

car fuel

Question 11

what is the use of kerosene

Answer 11

plane fuel

Question 12

what is the use of diesel

Answer 12

lorry fuel

Question 13

what is the use of fuel oil

Answer 13

ship fuel

Question 14

what is the use of bitumen

Answer 14

road tarmac

Question 15

what is fractional distillation and how does it work

Answer 15

crude oil is a mixture of many different things, fractional distillation separates them depending on their properties. it dies this by separating molecules with similar length chains which therefore have similar properties.

Question 16

what are the products of complete combustion of crude oil

Answer 16

CO2 and H2O

Question 17

what are the products of incomplete combustion of crude oil

Answer 17

CO and H2O
carbon monoxide is a toxic gas

Question 18

when does incomplete combustion of crude oil

Answer 18

when there is not enough oxygen

Question 19

why is CO2 a pollutant

Answer 19

its a greenhouse gas so it results in the enhanced greenhouse effect which leads to global warming

Question 20

why is CO (carbon monoxide) dangerous

Answer 20

it binds to haemoglobin which means you can carry less oxygen so you cant respire.

Question 21

why can N2 and O2 be dangerous

Answer 21

when at high temperatures they form NO (nitrogen oxide) which is a poisonous gas and when combined with water forms acid rain

Question 22

what is an impurity in crude oil

Answer 22

S (sulfur)

Question 23

why is sulfur dangerous

Answer 23

when combined with oxygen, sulfur forms sulfur dioxide which when combined with water forms acid rain

Question 24

why is acid rain bad

Answer 24

damages ecosystems, buildings, infrastructure, dangerous for wildlife

Question 25

what is cracking

Answer 25

the process of heating up longer chains to break them into smaller chains

Question 26

why do we use cracking

Answer 26

to make longer chains into smaller chains which are in higher demand

Question 27

why are smaller chains in higher demand

Answer 27

because they are more useful

Question 28

what is the catalyst used in cracking

Answer 28

aluminium oxide (Al2O3)

Question 29

what is the temperature needed to crack chains

Answer 29

600C

Question 30

what is the difference between alkanes and alkenes

Answer 30

alkanes are hydrocarbons with only single bonds and alkenes are hydrocarbons with one double C=C bond. alkanes are saturated, alkenes are unsaturated.

Question 31

What is the general formula for alkanes

Answer 31

CnH2n+2

Question 32

Name each of the first 6 alkanes in the homologous series in order of increasing number of carbon atoms

Answer 32

Methane Ethane Propane Butane Pentane Hexane

Question 33

What is the formula for methane

Answer 33

CH4

Question 34

What is the formula for ethane

Answer 34

C2H6

Question 35

What is the formula for propane

Answer 35

C3H8

Question 36

What is the formula for Butane

Answer 36

C4H10

Question 37

What is the formula for pentane

Answer 37

C5H12

Question 38

What is the formula for hexane

Answer 38

C6H14

Question 39

What is an isomer

Answer 39

A molecule with the same molecular formula but a different structural and displayed formula

Question 40

Why are alkanes unreactive

Answer 40

Because they have a very high activation energy as c-c bonds and C-H bonds are very strong. Same reason as for crude oil.

Question 41

What is an alkene

Answer 41

A hydrocarbon containing one C=C double bond. Unsaturated.

Question 42

What is the general formula for an alkene

Answer 42

CnH2n

Question 43

Are alkenes more or less reactive than alkanes and why

Answer 43

Alkenes are much more reactive than alkanes because they are unsaturated. The double bond in an alkene can easily open to allow two more atoms to join and leave a single bond between the carbons.

Question 44

What is the test for alkenes

Answer 44

Add bromine water, if it turns from orange to colourless then its and alkene. If remains orange its an alkane.