Organic Reactions

Question 1

What do all organic molecules contain

Answer 1

Carbon atoms

Question 2

What are functional groups

Answer 2

Double carbon bonds
Alcohol groups
Carboxylic acid groups
Esters

Question 3

What is the family of organic compounds with the same functional group called

Answer 3

Homologous series

Question 4

How does the homologous series differ

Answer 4

By an extra carbon atom that has 2 hydrogen atoms bonded to it

Question 5

Combustion of alkenes

Answer 5

Test ethene gas with lighted spill
Burn with yellow flame
Release less energy

Question 6

Addition reactions of alkenes

Answer 6

C=C
Double bond
More reactive than alkanes

Question 7

Alkenes reaction with halogens

Answer 7

Test ethene with bromine water

Orange to colourless

Question 8

Reaction with hydrogen

Answer 8

Do not contain maximum number of hydrogen atoms possible in hydrocarbon molecule
Reaction gets rid of double bond
Straightens molecules and increase melting points

Question 9

Reaction with steam

Answer 9

Ethanol = made from ethene gas
ethene + steam <=> ethanol
reversible

Question 10

The three homologous series

Answer 10

Alcohols, carboxylic acids, esters

Question 11

Alcohols

Answer 11

Removing H atom from alkane molecule by replacing it with -OH group
-OH functional group
Formula = C2H6O

Question 12

Carboxylic acids

Answer 12

-COOH functional group

Question 13

Esters

Answer 13

Closely related to carboxylic acids
Replace H atom
-COO- functional group
Structural formula of ethyl ethanoate = CH3COOCH2CH3

Question 14

Uses of alcohols

Answer 14

Fermenting sugars from plant material with yeast
Biofuel
Ethanol can be made with ethene and steam using a catalyst
Non-renewable source
Alcohols dissolve many of same substance as water
Smaller molecules mix well with water = neutral solutions
Dissolve other organic compounds

Question 15

Combustion with alcohols

Answer 15

Fuels
Flammable
Biofuel in cars
Blue flame
Ethanol + oxygen -> carbon dioxide + water

Question 16

Reaction with sodium

Answer 16

Produces H2

Gets smaller and smaller as it forms solution of sodium ethoxide in ethanol

Question 17

Oxidation

Answer 17

Combustion is one way to oxidise alcohol
Alcohol is oxidised to carboxylic acid when boiled with acidified potassium dichromate solution
Ethanol + oxygen atoms from oxidising agent -> ethanoic acid + water

Question 18

Tests for ethanoic acid

Answer 18

1) take pH
2) add potassium carbonate to acid
3) add magnesium ribbon to acid
4) test conductivity using simple circuit of cell, 2 carbon electrodes and bulb
5) collect gas given off from negative electrode with lighted spill

Question 19

Why are carboxylic acids called weak acids

Answer 19

CO2 given off slowly when metal carbonate reacts with carboxylic acid
Carboxylic acids = weak acids
Strong acids ionise complete and weak acids dont
Reversible reaction takes place

Question 20

Making esters

Answer 20

Carboxylic acid + alcohol ->(acid catalyst)-> ester + water