C 9 + 10

Question 1

mixture

Answer 1

-when some elements or compounds are mixed together and intermingle but do not react together
-not pure substance
-no new substance made

Question 2

hydrocarbon

Answer 2

compound containing only hydrogen and carbon

Question 3

fractions

Answer 3

hydrocarbons with similar boiling points separated from crude oil

Question 4

distillation

Answer 4

separation of a liquid from a mixture by evaporation followed by condensation

Question 5

alkanes

Answer 5

saturated hydrocarbon
general formula = C n H 2n+2
(methane, ethane, propane)

Question 6

saturated hydrocarbons

Answer 6

hydrocarbon with only single bonds between its carbon atoms
contains as many hydrogen atoms as possible in each molecule.

Question 7

flammable

Answer 7

easily ignited and capable of burning rapidly

Question 8

fractional distillation

Answer 8

a way to separate liquids from a mixture of liquids by boiling off the substances at different temperatures, then condensing and collecting the liquids

Question 9

oxidised

Answer 9

describe a substance that has had oxygen added to it

Question 10

cracking

Answer 10

reaction used in oil industry to break down large hydrocarbons into smaller, more useful ones

Question 11

thermal decomposition

Answer 11

breakdown of compound by heating it

Question 12

alkene

Answer 12

unsaturated hydrocarbon which contains a carbon-carbon double bond.
general formula = C n H 2n
-react with orange bromine turning it colourless

Question 13

double bond

Answer 13

covalent bond made by sharing of two pairs of electrons

Question 14

unsaturated hydrocarbon

Answer 14

a hydrocarbon whose molecules contains at least one carbon-carbon double bond

Question 15

functional group

Answer 15

atom or group of atoms that give organic compounds their characteristic reactions

Question 16

homologous series

Answer 16

a group of related organic compounds that have the same functional group

Question 17

fermentation

Answer 17

reaction in which the enzymes in yeast turn glucose into ethanol and carbon dioxide

Question 18

crude oil

Answer 18

mixture of many different compounds (mainly hydrocarbons)

Question 19

what does the properties of fractions depend on

Answer 19

-size of hydrocarbon molecules in it
-lighter factions are better fuels- ignite easily, burn well and cleaner flames

Question 20

what happens when hydrocarbons are burned

Answer 20

carbon and hydrogen in the fuel are completely oxidised

Question 21

tests for gases formed in complete combustion of hydrocarbon:

Answer 21

-carbon dioxide tuns limewater cloudy
-water turns blue cobalt chloride paper pink
water turns white hydrous copper sulphate blue

Question 22

what does incomplete combustion of a hydrocarbon produce

Answer 22

carbon monoxide

Question 23

how can you break large hydrocarbon molecules into smaller molecules

Answer 23

-passing vapours over a hot catalyst
-mixing them with steam and heating them to a very high temperature

Question 24

what does complete combustion of an alkene form

Answer 24

carbon dioxide and water

Question 25

how can alkene form a saturated molecule

Answer 25

react with halogens, hydrogen and water by adding atoms across the c=c bond

Question 26

what are the functional groups of the homologous series

Answer 26

alcohols - -OH carboxylic acids - -COOH esters - -COO-

Question 27

uses of alcohols

Answer 27

-solvents -fuels -ethanol is the main alcohol in alcoholic drinks

Question 28

what do alcohols produce when they burn

Answer 28

carbon dioxide and water

Question 29

what happens when alcohols react with sodium metal

Answer 29

form solution of sodium alkoxide and gives of hydrogen gas

Question 30

how can ethanol be oxidised to ethanoic acid

Answer 30

-chemical oxidising agents -action of microbes in the air

Question 31

carboxylic acid

Answer 31

-pH less than 7 -carbonates gently fizz in solutions of carboxylic acids, releasing carbon dioxide

Question 32

aqueous solutions of carboxylic acids

Answer 32

-weak acids -higher pH value than solutions of strong acids of the same concentration

Question 33

how are esters made

Answer 33

reacting a carboxylic acid with an alcohol, in the presence of a strong acid catalyst

Question 34

esters use

Answer 34

flavourings and perfume