Organic

Question 1

Hydrocarbon

Answer 1

A compound containing only the elements hydrogen and carbon

Question 2

Saturated

Answer 2

An organic compound in which all the bonds are single bonds

Question 3

Homologous series

Answer 3

Series of organic compounds that have the same general formula, similar chem reactions abs where each member differs from the next by a -CH2- group

Question 4

Unsaturated

Answer 4

An organic compound that contains a carbon-carbon double bond

Question 5

General formula

Answer 5

A formula that states the ratio of atoms of each element in the formula of every compound in a particular homologous series

Question 6

Isomerism

Answer 6

Compounds that have same molecular formula but diff displayed formula
Diff compounds called isomers

Question 7

Alkanes

Answer 7

CnH2n+2

    H
     |
H-C-H
     |
    H

Question 8

Methane

Answer 8

CH4

Question 9

Ethane

Answer 9

C2H6

Question 10

Propane

Answer 10

C3H8

Question 11

Butane

Answer 11

C4H10

Question 12

Pentane

Answer 12

C5H12

Question 13

Isomers of butane

Answer 13

Methyl butane (one strand off)

Question 14

Isomers of propane

Answer 14

Methyl propane

Dimethylpropane

Question 15

Combustion of Alkanes

Answer 15

Burn w oxygen when heated in air

Plentiful supply= co2 + h2o

Insufficient supply = co + h20
(Carbon monoxide)
Poisonous
Reduces capacity of the blood to carry oxygen

Question 16

Alkanes and bromine

Answer 16

Methane and bromine react together in UV light to form bromomethane

Substitution reaction- one atom in methane replaced with an atom of bromine

CH4 + Br2 -> CH3Br + HBr

Question 17

Alkenes

Answer 17

CnH2n

H.          H
   \         /
     C=C
  /          \
H           H

Question 18

Ethene

Answer 18

C2H4

Question 19

Propene

Answer 19

C3H6

Question 20

Butene

Answer 20

C4H8

Question 21

Pentene

Answer 21

C5H10

Question 22

Isomers for C4H8

Answer 22

But-1-ene

But-2-ene

Methylpropene

Question 23

Addition reactions

Answer 23

With halogens

Bromine can be added into an Alkene and will add across the double bond to form dibromoethane

C2H4 + Br2 -> C2H4Br2

Can be used to test for the presence of a carbon-carbon double bond
decolorisation of bromine

Question 24

Ethanol method 1

Answer 24

Fermentation.

Dissolve starch or sugar in water and add yeast
Leave mixture to ferment at 25-40*c in absence of air
Filter off excess yeast to obtain dilute solution of ethanol
If ethanol content is above 15% then yeast will be killed
More conc solution needs to be distilled
C6H12O6 -> 2C2H5OH + 2CO2

Question 25

Ethanol method 2

Answer 25

Direct hydration of Ethene A mixture of Ethene and steam is passed over phosphoric acid catalyst at a temp of 300*c and 60-70 atmospheres of pressure Ethanol is condensed as a liquid Ethene required is taken from crud oil C2H4 + H2O -> C2H5OH

Question 26

Comparing methods of ethanol manufacturing

Answer 26

``` F Uses renewable resources Batch process V slow process Produces dilute solution Low temps required ``` ``` H of e Non renewable resources(no more crude oil is a danger) Continuous process Fast process Produces pure ethanol High temps and pressures - costly ```

Question 27

Combustion of ethanol

Answer 27

Burns w oxygen when heated in air Can be used as fuel C2H5OH + 3O2 -> 2CO2 + 3H2O

Question 28

Dehydration of ethanol

Answer 28

Can be dehydrated by passing ethanol vapour over hot aluminium oxide which acts as a catalyst C2H5OH -> C2H4 + H2O Can be used to manufacture Ethene for production of polyethene Most Ethene made from cracking crude oil fractions