organic chemistry

Question 1

hydrocarbon

Answer 1

any compound formed between hydrogen and carbon only

Question 2

alkanes

Answer 2

saturated compounds (single carbon bonds)

Question 3

methane

Answer 3

-one carbon atom with hydrogen bonds
-ch4 formula

Question 3

ethane

Answer 3

-two carbon atoms bonding with 3 hydrogen atoms each
-CH6 formula

Question 3

propane

Answer 3

-three carbon bonds with 8 hydrogen atoms
-CH8 formula

Question 3

butane

Answer 3

4 carbon atoms with 10 hydrogen atoms
CH10 formula

Question 4

homolgous series

Answer 4

similar properties reacting in a diffrent way

Question 5

isomers

Answer 5

molecules that have the same molecular formula but different structural formula

Question 5

alkane proterties

Answer 5

-boiling point increases with chain length

-gas to liquid to solid further down chain

-longer alkanes are more viscious

-shorter alkanes are more flammable

Question 6

viscious

Answer 6

thick and sticky

Question 7

complete combustion

Answer 7

-hydrocarbon + oxygen > carbon dioxide +water
-for fuel (exothermic reaction)

Question 8

crude oil

Answer 8

-made of of diffrent hydrocarbons

crude oil can be seperated into fractions,

Question 9

fractions

Answer 9

-simpler, more useful hydrocarbons of diffrent lengths

Question 10

fractional distillation

Answer 10

-fractions of crude oil can be separated by fractional distillation

-oil is heated until it turns into a gas, gasses enter fractioning column

Question 11

how does fractional distillation work

Answer 11

longer hydrocarbons have higher boiling points . when they reach boiling point, they condense back into a liquid and drain near the bottom

shorter hydrocarbons condense later due to their lower boiling points

Question 12

List the fractions from lowest to highest boiling point

Answer 12

Refinery gases- domestic heating and cooking
Petrol- fuel for cars
kerosene- fuel for aircraft
diesel oil- fuel for ships
bitumen- surface of roads

Question 13

cracking

Answer 13

-form of thermal decomposition

-turns long saturated alkanes into smaller saturated alkanes and an alkene

Question 14

what does cracking involve

Answer 14

heat, and a catalyst
vaporised hydrocarbons are passed over a powdered catalyst.

longer chained molecules are split apart on the surface of a catalyst

Question 15

name a catalyst used for cracking

Answer 15

aluminium oxide

Question 16

what is incomplete combustion

Answer 16

not enough oxygen for complete combustion

Question 17

products of incomplete combustion

Answer 17

carbon monoxide and soot

Question 18

dangers of carbon monoxide

Answer 18

-carbon monoxide binds with haemoglobin in red blood cells, and reduces the amount of blood flowing around the body
-lack of oxygen in blood supply can lead to a coma or death

Question 19

dangers of soot

Answer 19

tiny particles of carbon are released into atmosphere and when falls, soot can cause poor air quality and respiratory problems

Question 20

alkenes

Answer 20

hydrocarbons that fit the general formula CnH2n
except they have one C–C double bond in their carbon chain

Question 21

ethene

Answer 21

c2H4

Question 22

propene

Answer 22

C3H6

Question 23

butene

Answer 23

C4H8

Question 24

Pentene

Answer 24

C5H10

Question 25

alkenes reaction with bromine

Answer 25

alkenes react with bromine by breaking the C–C and adding the bromine atoms in

C2H4+ Br2> C2H4Br2
addition reaction(adding bromine atoms into alkene)
reaction happens without uv light- alkenes more reactive than alkanes
works with bromine water (orange)
turns orange to colourless

Question 26

addition polymer

Answer 26

molecules with a C–C double bond add into chains
small molecules add together are called monomers
long chain they form are called polymers

Question 27

common polymers

Answer 27

polyethene- drinks bottles shopping bags
propene- storage boxes, climbing ropes
chloroethene- wire insulation, drainspipes