C10

Question 1

homologous series

Answer 1

a family of organic compounds with the same functional group

Question 2

functional group

Answer 2

eg. C–C (double bond)

Question 3

first 4 alkene molecules

Answer 3

starts as ethene as needs 2 to double bond

ethene, propene, butene, pentene

Question 4

complete combustion of alkenes

Answer 4

alkene _ oxygen –> carbon dioxide + water.

however- tend to burn with a smokier flame than alkanes as incomplete combustion happens.

Question 5

addition reactions of the alkenes

Answer 5

double bond means they are more reactive than alkanes
react by addition reactions.
atoms added across C-C double bond so a C-C single bond is formed.

Question 6

alkenes and halogens

Answer 6

halogen atoms add across double bond.

eg. ethene + bromine -> dibromoethane

Question 7

alkenes + hydrogen

Answer 7

60 degrees in the presence of a nickel catalyst
produces alkanes
alkenes + hydrogen –> alkanes
eg. butene + hydrogen —> butane
(catalyst)

Question 8

alkenes and steam

Answer 8

alkene + steam –> alcohols
reversible reaction

ethene + steam —–> butane

Question 9

alcohols

Answer 9

functional group OH

first 4 members methanol, ethanol, propanol, butanol.

Question 10

structural formula of ethanol

Answer 10

CH3CH2OH

Question 11

carboxylic acids

Answer 11

functional group COOH

first 4 members: methanoic acid, ethanoic acid, propanoic acid, butanoic acid

Question 12

esters

Answer 12

functional group COO
eg. ethyl ethanoate.
distinctive pleasant sweet or fruiy smells
volatile compounds - easily evaporate
used as flavourings and in perfumes

Question 13

alcohols plus water

Answer 13

alcohols with smaller molecules like methanol, ethanol and propanol mis well with water to produce neutral solutions

Question 14

why are alcohols used as solvents

Answer 14

many organic solvents dissolve in alcohols so they are used as solvents in products like perfumes and mouthwashes.

Question 15

ethanol

Answer 15

manufactured by fermentation- where yeast converts sugars from plant material into an aqueous solution of ethanol
main alcohol in wine, beer and other alcoholic drinks.
in some countries, ethanol is available as an alternative fuel to petrol or diesel. Ethanol made by fermentation is a biofuel

Question 16

alcohols burning in air

Answer 16

alcohol + oxygen —> carbon dioxide + water
alcohols are fuels and they can be mixed with petrol
ethanol is used as a biofuel in cars
ethanol + oxygen —> carbon dioxide + water

Question 17

sodium plus alcohols

Answer 17

sodium reacts with alcohols to produce hydrogen gas, but less vigorous reaction than sodium and water

Question 18

alcohols plus chemical oxidising agents

Answer 18

alcohols can be oxidised by chemical oxidising agents like potassium dichromate to produce carboxylic acids
some microbes in the air can also oxidise solutions of ethanol to produce ethanoic acid, which turns alcoholic drinks sour- main acid in vinegar.

Question 19

carboxylic acids and water

Answer 19

carboxylic acids dissolve in water to produce neutral solutions with a pH less than 7.
have properties typical of all acids
eg, when added to carbonates they fizz as they react to produce carbon dioxide, a salt and a water.

Question 20

why are carboxylic acids different to other acids

Answer 20

they react with alcohols in the prescence of an acid catalyst to produce esters
eg. ethanol and ethanoic acid react in the prescence of a sulfuric acid catalyst to produce ethyl ethanoate and water

Question 21

carboxylic acids are weak acids because…

Answer 21

when it dissolves it doesnt ionise completely, most molecules remain as molecules in the solution
reversible reaction.
eg. ethanoic acid
CH3COOH(aq) —–> CH3COO- (aq) + H+ (aq)