organic chemistry (67-74, 79) (paper 1)

Question 1

define empirical formula

Answer 1

the simplest whole numbre ratio of atoms of each element in a compound

Question 2

what do compounds in a homologous series share in common

Answer 2

• same general formula
• same functional group
• react in similar ways

Question 3

what is the functional group for an alkene

Answer 3

C=C - carbon carbon double bond

Question 4

what is the stem for 1 carbon in a compound

Answer 4

meth-

Question 5

what is the stem for 2 carbon in a compound

Answer 5

eth-

Question 6

what is the stem for 3 carbon in a compound

Answer 6

prop-

Question 7

what is the stem for 4 carbon in compound

Answer 7

but–

Question 8

what is the prefix for an alkane

Answer 8

-ane

Question 9

what is the prefix for an alkene

Answer 9

-ene

Question 10

what is the general formula for alkanes

Answer 10

CnH2n+2

Question 11

what is the general formula for alkenes

Answer 11

CnH2n

Question 12

what is the general formula for alcohols

Answer 12

CnH2n+1OH

Question 13

define hydrocarbon

Answer 13

molecules made up of only carbon and hydrogen atoms

Question 14

define saturated

Answer 14

only containing single bonds between carbon atoms

Question 15

define unsaturated

Answer 15

have double or triple bonds between carbon atoms

Question 16

define isomer

Answer 16

molecules with the same molecular formula but different structual formulae

Question 17

what are the rules for isomers

Answer 17

• take one carbon off the long chain
• re-bond that carbon to the original chain at least one carbon from the end

Question 18

what is crude oil

Answer 18

a mixture of molecules

Question 19

what is the process which seperates out crude oil

Answer 19

fractional distilation

Question 20

describe fractional distilation of crude oil

Answer 20

• the oil is heated until it vapourises
• the vapours rise up the column until just below their bloiling point and condense
• the column is coller and the top than the bottom
• larger molecules with higher boiling points condense at the bottom

Question 21

what is the order of products from crude oil fractional distilation from top to bottom

Answer 21

• refinery gases
• gasoline
• kerosene
• diesel
• fuel oil
• bitumen

Question 22

what are the physical properties of the longer hydrocarbons

Answer 22

• larger molecules
• more viscous
• more yellow / orange

Question 23

why are short-chain hydrocarbons more useful than long chain molecules

Answer 23

• they ignite more easily
• can be used as fuels
  but there is a larger supply of long chain hydrocarbons

Question 24

how is the demand met for smaller hydrocarbons

Answer 24

long hydrocarbons are split into smaller molecules by a process of catalytic cracking

Question 25

what are the conditions are catalytic cracking

Answer 25

- 600-700 degress celcius - catalyst of silica or alumina

Question 26

what type of reaction is combustion

Answer 26

exothermic

Question 27

what are the two types of combustion

Answer 27

- complete combustion - incomplete combustion

Question 28

what are the conditions and results for complete combustion

Answer 28

- lots of O2 - releases CO2 and H2O

Question 29

what are the conditions and results for incomplete combustion

Answer 29

- limited O2 - releases CO, C and H2O (toxic carbon monoxide and soot)

Question 30

what are the affects environmentally from combustion

Answer 30

- CO2 = greenhouse gas = global warming - CO = toxic, prevents oxygen in blood - SO2 = acid rain

Question 31

define volatile

Answer 31

when something quickly changes from a liquid to a vapour

Question 32

are alkanes saturated or unsaturated

Answer 32

saturated

Question 33

whats more reactive alkanes or alkenes and why

Answer 33

alkenes - due to the C=C

Question 34

what are alkenes used to produce

Answer 34

plastics

Question 35

how do you distinguish between alkenes and alkanes

Answer 35

react them with bromine water

Question 36

what is formed when alkanes or alkenes react with halogens

Answer 36

haloalkanes

Question 37

describe how alkenes react with bromine water & what type of reaction is it

Answer 37

- rapidly decoloursies - orange to colourless - addition reaction - C2H4Br2

Question 38

descirbe how alkanes react with bromine water & what type of reaction is it

Answer 38

- only react with intense UV light - substitution reaction - C2H5Br + HBr

Question 39

when are alkenes produced

Answer 39

when large hydrocarbon moleules are cracked into smaller hydrocarbon molecules

Question 40

what are addition polymers made from

Answer 40

unsaturated monomers

Question 40

what are addition polymers

Answer 40

aubstances of high average relative molecular mass made by joining lots of small units called monomers

Question 41

what must monomers have to make a polymer

Answer 41

a double covalent bond

Question 42

what is the process called where monomers join to creat a polymer

Answer 42

addition polymerisation

Question 43

how would you right a polymer of ethene

Answer 43

poly(ethene)

Question 44

how do you draw a polymer

Answer 44

a repeat unit

Question 45

describe what is needed in a repeat unit for a polymer

Answer 45

- brackets - continued bonds outside the brackets - only the bit that used to have the double bond - an n outside the bracket

Question 46

define inert

Answer 46

dont react easily

Question 47

are addition polymers inert

Answer 47

yes

Question 48

why are addition polymers inert

Answer 48

because the carbon-carbon bonds in the polymer chain are very strong and are not easily broken

Question 49

how does the fact that polymers are inert affect the environment

Answer 49

- very long time to biodegrade - buring them releases toxic gases - have to reuse and recycle