AQA GCSE Chemistry Paper 2 notes

Chemistry

Unit 6- The rate and extent of chemical changes.

●​ Rate of reaction
-​ Calculating rates of reaction
-​ Factors which affect the rates of chemical reactions.
-​ Collision theory and activation energy
-​ Catalysts
●​ Reversible reactions and dynamic equilibrium
-​ Reversible reactions
-​ Reversible reactions and energy changes
-​ Equilibrium
-​ The effect of changing conditions on equilibrium (HT only)
-​ The effect of changing concentration (HT only)
-​ The effect of temperature changes on equilibrium (HT only)
-​ The effect of pressure changes on equilibrium (HT only)

Unit 7- Organic chemistry​

●​ Carbon compounds as fuels and feedstock
-​ Crude oil, hydrocarbons and alkanes.
-​ Fractional distillation and petrochemicals
-​ Properties of hydrocarbons
-​ Cracking and alkenes
●​ Reaction of alkenes and alcohols
-​ Structure and formula of Alkenes
-​ Reactions of Alkenes
-​ Alcohols
-​ Carboxylic acids
●​ Synthetic and naturally occurring polymers
-​ Addition polymerisation
-​ Condensation polymerisation (HT only)
-​ Amino acids (HT only)
-​ DNA and other naturally occurring polymers

,Unit 8- Chemical Analysis

●​ Purity, Formulations and chromatography
-​ Pure substances
-​ Formulations
-​ Chromatography
●​ Identification of common gases
-​ Test for hydrogen
-​ Test for oxygen
-​ Test for carbon dioxide
-​ Test for chlorine
●​ Identification of ions by chemical and spectroscopic means
-​ Flame tests
-​ Metal hydroxides
-​ Carbonates
-​ Halides
-​ Sulfates
-​ Instrumental methods
-​ Flame emission spectroscopy

Unit 9- Chemistry of the atmosphere

●​ The composition and evolution of the world's atmosphere
-​ The proportions of different gases in the atmosphere
-​ The earth's early atmosphere
-​ How oxygen increased
-​ How carbon dioxide increased
●​ Carbon dioxide and methane as greenhouse gases
-​ Greenhouse gases
-​ Human activities which contribute to an increase in greenhouse gases
-​ Global climate change
-​ The carbon footprint and its reduction
●​ Common atmospheric pollutants from fuels
-​ Atmospheric pollutants from fuels
-​ Properties and effects of atmospheric pollutants

Unit 10- Using resources

●​ Using the earth's resources and obtaining potable water
-​ Using the earth's resources and sustainable development
-​ Potable water
-​ Waste water treatments
-​ Alternative methods of extracting metals
●​ Life cycle assessment and recycling
-​ Life cycle assessment
-​ Ways of reducing the use of resources
●​ Using materials
-​ Corrosion and its prevention

, -​ Alloys as useful materials
-​ Ceramics, polymers and composites
●​ The Haber process and the use of NPK fertilizers
-​ The Haber process
-​ Production and uses of NPK fertilizers

, Rate of reaction

-​ Calculating rates of reaction
-​ Collision theory and activation energy
-​ Factors which affect the rates of chemical reactions.
-​ Catalysts

Calculating rates of reaction

Quantity of product formed against time




The slope of the line gives us an idea of the rate of the reaction. The steeper the slope the
faster the reaction.
Initially, there is a high concentration of reactant particles, so there are more frequent
successful collisions and the reaction is faster. This is because we have a large number of
reactant molecules so lots of them are reacting and forming the product.
Gradually the slope of the line becomes less steep. This tells us the reaction is slowing
down. In other words the rate of reaction is decreasing. This is because a lot of the reactant
molecules have already reacted and turned into products. This means there are fewer
reactant molecules available to react. At the end the slope of the line is now zero, in other
words the line is flat. The reaction reaches a point where no more measurable product is
being formed, so the graph becomes horizontal.