Section 3 a) Specification

3.1 explain the terms homologous series, hydrocarbon, saturated, unsaturated, general formula and isomerism.

A homologous series is a group of compounds with the same general formula and similar chemical properties.
A hydrocarbon is a compound made up of only hydrogen and carbon particles.
Saturated means that a compound is made up of only single bonds, it has no double bonds. Alkanes are a homologous series of saturated hydrocarbons.
Unsaturated means that a compound includes double bonds. Alkenes are a homologous series of unsaturated hydrocarbons.
A general formula is a type of empirical formula that represents of all of the members of a homologous series.
Isomers are molecules with the same chemical formula but different structures (e.g. diamond and graphite are both carbon, but are very different because they are isomers)

Section 3 Specification

a) Introduction

3.1 explain the terms homologous series, hydrocarbon, saturated, unsaturated, general formula and isomerism.


b) Alkanes 

3.2 recall that alkanes have the general formula CnH2n+2

3.3 draw displayed formulae for alkanes with up to five carbon atoms in a molecule, and name the straight-chain isomers

3.4 recall the products of the complete and incomplete combustion of alkanes 3.5 describe the substitution reaction of methane with bromine to form bromomethane in the presence of UV light.


c) Alkenes 

3.6 recall that alkenes have the general formula CnH2n

3.7 draw displayed formulae for alkenes with up to four carbon atoms in a molecule, and name the straight-chain isomers (knowledge of cis- and transisomers is not required)

3.8 describe the addition reaction of alkenes with bromine, including the decolourising of bromine water as a test for alkenes.


d) Ethanol 

3.9 describe the manufacture of ethanol by passing ethene and steam over a phosphoric acid catalyst at a temperature of about 300°C and a pressure of about 60–70 atm

3.10 describe the manufacture of ethanol by the fermentation of sugars, for example glucose, at a temperature of about 30°C

3.11 evaluate the factors relevant to the choice of method used in the manufacture of ethanol, for example the relative availability of sugar cane and crude oil

3.12 describe the dehydration of ethanol to ethene, using aluminium oxide.

Section 2 g) Specfication

2.37 describe tests for the cations:
i Li+, Na+, K+, Ca2+ using flame tests
ii NH4 +, using sodium hydroxide solution and identifying the ammonia evolved
iii Cu2+, Fe2+ and Fe3+, using sodium hydroxide solution

2.38 describe tests for the anions:
i Cl- , Br- and I- , using dilute nitric acid and silver nitrate solution
ii SO4 2- , using dilute hydrochloric acid and barium chloride solution
iii CO3 2- , using dilute hydrochloric acid and identifying the carbon dioxide evolved

2.39 describe tests for the gases:
i hydrogen
ii oxygen
iii carbon dioxide
iv ammonia
v chlorine.

Section 2 f) Summary

Metals can be placed in an order of most to least reactive, called the reactivity series.

This can be remembered using an acronym:
Please
Stop
Calling
Me
A
Cranky
Zebra
I
Teach
Lions
How
Cars
Save
Gold
Printers

More reactive metals will displace less reactive ones in a compound (e.g. a metal salt or a metal oxide), which can be demonstrated by dissolving the compound in water to make it aqueous, then adding another metal to see if it reacts; if it does, then it is more reactive. If it doesn't, it's less reactive.
Reactivity series can also be determined by evaluating the intensity of reaction with water or acid.

Sacrificial protection
Iron is a useful metal, and it's on the less reactive side. But, when exposed to water and air, it will rust. It can be protected using grease, oil, paint or plastic, but another method is galvanising.
Galvanising is a form of sacrificial protection, wherein the iron is coated in a layer of zinc, which is a more reactive metal. This causes the oxygen and water to react with the zinc instead of the iron, protecting it. This method can be employed in different metals, but is called sacrificial protection and not galvanising in this case.

Section 2 f) Key Words

Galvanising: Coating iron in zinc as a form of sacrificial protection.

Oxidation: Gain of oxygen ions.

Reactivity series: The order in which metals will react with a non-metal, more reactive metals displacing less reactive metals.

Reduction: Loss of oxygen ions.

Rust: Compound formed when iron reacts with water and oxygen.

Sacrificial protection: Coating a less reactive metal in a more reactive metal, so the more reactive metal reacts with the surroundings and the less reactive metal is protected.

Section 2 f) Specification

2.29 understand that metals can be arranged in a reactivity series based on the reactions of the metals and their compounds: potassium, sodium, lithium, calcium, magnesium, aluminium, zinc, iron, copper, silver and gold

Some metals are more reactive than others, based on their chemical compositions. More reactive metals will displace less reactive metals in a compound, and they react more strongly. From reactions, we can determine the reactivity series (from most to least reactive):

Potassium K
Sodium Na
Lithium Li
Calcium Ca
Magnesium Mg
Aluminium Al
Zinc Zn
Iron Fe
Copper Cu
Silver Ag
Gold Au

2.30 describe how reactions with water and dilute acids can be used to deduce the following order of reactivity: potassium, sodium, lithium, calcium, magnesium, zinc, iron and copper

Potassium, sodium, and lithium are alkali metals, therefore their reactivity series is easily determined by reacting them with cold water. Calcium also reacts with water, but less so. Magnesium, zinc, and iron will only react with cold water very slowly, but will react with acids (e.g. hydrochloric acid) with varying degrees of intensities. 
Copper will not react with either an acid or water.
The more vigorous the reaction, the more reactive the metal.

2.31 deduce the position of a metal within the reactivity series using displacement reactions between metals and their oxides, and between metals and their salts in aqueous solutions

To carry out a reaction to determine reactivity series, dissolve a metal oxide or metal salt in water, then add another metal. If there is a reaction, the metal you introduced is more reactive. If there is no reaction, it is less reactive. This can be done multiple times with different metals to determine reactivity series.

2.32 understand oxidation and reduction as the addition and removal of oxygen respectively

OILRIG says Oxidation Is Loss of electrons and Reduction Is Gain of electrons, but it can also be in reference to loss or gain of an oxygen ion, as they are positively charged; they have more protons than electrons. Oxidation is gain of oxygen ions and reduction is loss of oxygen ions. This is easily memorable as 'oxidation' is rooted from the word oxygen.

2.33 understand the terms redox, oxidising agent, reducing agent

Redox means a reaction involving molecules that are reduced and molecules that are oxidised.
An oxidising agent is a less reactive metal in a compound that allows the other metal to be oxidised.
A reducing agent is a more reactive metal that reduces the other metal.

2.34 describe the conditions under which iron rusts

Under conditions where there is moisture and air; it requires both oxygen and water to rust.

2.35 describe how the rusting of iron may be prevented by grease, oil, paint, plastic and galvanising

Grease, oil, paint or plastic creates a layer between the iron and air and water. It repels water and doesn't allow air in.
Galvanising is a technique of coating iron with zinc, a more reactive metal. The air and water react with the zinc instead of the iron, and preventing the iron from coming into contact with the air.

2.36 understand the sacrificial protection of iron in terms of the reactivity series.

Sacrificial protection means a more reactive metal is made to coat a less reactive one, it then reacts with the air and water instead of the iron.

Section 2 e) Summary

When a metal reacts with an acid, it forms a salt and hydrogen. It is easily remembered by MASH
Metal
+
Acid
-->
Salt
+
Hydrogen

When hydrogen reacts with oxygen, it releases a lot of energy in the form of heat and light. This creates a flame, making it a combustion reaction.

2H2 + O2 --> 2H2O + energy

This reaction produces pure water as well as energy. We can test for water in a few different ways:

Testing for water

Physical test: Heat the water and see if it boils at 100℃, in which case it is pure.

Chemical test: Expose to anhydrous copper (II) sulphate, a white substance. It will turn blue in presence of water.

Section 2 e) Key Words

Chemical Test: A test involving the chemical molecules, and the way they react with other molecules. e.g. test for water using anhydrous copper (ii) sulphate.

Combustion: Reaction with oxygen that produces a flame (a lot of heat and light energy is released)

Physical Test: A test involving the physical properties of a molecule, e.g. boiling point of water.

Section 2 e) Specification

2.25 describe the reactions of dilute hydrochloric and dilute sulfuric acids with magnesium, aluminium, zinc and iron

The rule "MASH" tells us that when a metal reacts with an acid, a salt will be produced, as well as hydrogen.

Metal + Acid --> Salt + Hydrogen

e.g.

Mg(s) + 2HCl(aq) --> MgCl2 + H2

2.26 describe the combustion of hydrogen

The combustion of hydrogen is its reaction with oxygen. It is exothermic, so a lot of energy is produced, as well as pure water.

2H2 + O2 --> 2H2O

2.27 describe the use of anhydrous copper(II) sulfate in the chemical test for water

If anhydrous copper sulphate changes from white to blue, it has become hydrous copper sulphate and it contains water.

2.28 describe a physical test to show whether water is pure.

Heat the water until it boils, with a thermometer. If it boiled at 100℃ exactly, it is pure water.