chemistry paper 2

Question 1

what is a hydrocarbon

Answer 1

and compound formed from hydrogen and oxygen atoms only

Question 2

what is the general formula of alkanes

Answer 2

CnH2n+2

Question 3

are alkanes saturated or unsaturated

Answer 3

saturated

Question 4

the shorter the hydrocarbon chain, the ….?

Answer 4

less viscous, more volatile and more flammable

Question 5

what is the general formula of alkenes

Answer 5

CnH2n

Question 6

are alkenes saturated or unsaturated

Answer 6

unsaturated

Question 7

what can alkenes do that alkanes can not

Answer 7

form bonds from using the free carbon atoms. this makes them reactive

Question 8

what is crude oil

Answer 8

a mixture of hydrocarbons former over many years

Question 9

explain fractional distillation

Answer 9

oil is heated and enters the column as a vapour, longer hydrocarbons have high boiling pints and condense early on, shorter hydrocarbons have lower boiling points and condense at the top

Question 10

what is cracking

Answer 10

when longer alkene molecules are turned into smaller, more useful ones

Question 11

what kind of reaction is cracking

Answer 11

thermal decomposition

Question 12

what catalyst is used in cracking

Answer 12

aluminium oxide

Question 13

how do alkenes normally react

Answer 13

addition reactions

Question 14

what is addition of hydrogen in an alkene

Answer 14

hydrogenation. it forms alkanes

Question 15

what happens when water vapour reacts with alkenes

Answer 15

alcohols are formed

Question 16

what happens when halogens react with alkenes

Answer 16

they form a saturated compound

Question 17

how do alkenes burn

Answer 17

with a smoky flame. sometimes carbon and carbon monoxide are formed

Question 18

functional group of carboxylic acids?

Answer 18

-COOH

Question 19

what do carboxylic acids and alcohols form when reacted

Answer 19

esters

Question 20

functional group of esters?

Answer 20

-COO

Question 21

functional group of alcohols?

Answer 21

-OH

Question 22

what are the properties of alcohols

Answer 22

they are flammable, the first 4 are soluble in water and they react with sodium, always producing hydrogen

Question 23

how are polyesters made

Answer 23

condensation polymerisation

Question 24

what is condensation polymerisation

Answer 24

monomers with different functional groups reacting together and forming bonds

Question 25

what polymers make proteins

Answer 25

polypeptides via condensation polymerisation

Question 26

what polymer is dna made from

Answer 26

two chains of nucleotides

Question 27

how does dna get its double helix structure

Answer 27

the bases pair up with each other to form cross links

Question 28

what temperature and pressure is equilibrium at for ammonium

Answer 28

450oC and 200 atmospheres

Question 29

how do npk fertilisers assist with plant growth

Answer 29

they contain salts of nitrogen, phosphorus and potassium, which all affect growth

Question 30

test for chlorine

Answer 30

bleaches damp litmus paper

Question 31

test for oxygen

Answer 31

relights a glowing splint

Question 32

test for carbon dioxide

Answer 32

turns limewater cloudy

Question 33

test for hydrogen

Answer 33

puts out a splint with a squeaky pop

Question 34

test for sulphates

Answer 34

add HCL and BaCL2 to a test tube, and see if it forms a white precipitate

Question 35

how is ammonia collected

Answer 35

it is formed as a gas, but liquefies in the condenser and removed