Topic 1 - Stoichiometric Relationships

Stoichiometry deals with all the stuff about the amounts of chemicals involved and produced in chemical reactions, and the ratios in which they react. It is traditionally a pain in the backside for many students but is one of those things that is too important to let yourself not understand, as it is assumed knowledge in all the other topics, and so you can’t succeed in them without it. If you are finding stoichiometry difficult, the main thing is to practice. 

Topic 2 & 12 - Atomic structure

The atomic structure unit is, somewhat unsurprisingly, about the structure of atoms. You will learn about the component parts of atoms (protons neutrons and electrons) and how they are arranged within an atom, especially the ‘shell’ model of electron arrangement; we will then look at mass spectrometry and emission spectroscopy and the evidence these can provide to support our understanding of the atom . If you are a Higher Level student, you will progress beyond the shell model of electron arrangement to look at the idea of orbitals, and some of the evidence we have for them.

topic 3 & 13- Periodicity & Transition Metals

Periodicity is concerned with the trends and patterns in the  physical and chemical behaviour of the elements in the periodic table. In this unit we will look at:

• The structure and nature of the periodic table
• Trends in physical properties across periods and down groups
• Trends in chemical properties across periods and down groups
• Transition metal complexes.

topic 4 & 14 - chemical bonding & Structure

The bonding unit builds on the understanding of bonding developed at IGCSE level, to consider in great depth the actual mechanics of bonding, and how this impacts the physical properties of compounds.
Whilst the topic does cover metallic and ionic bonding, it focuses overwhelmingly on covalent bonding looking at and we will consider:

• The shapes of molecules
• The polarity of molecules
• The intermolecular forces between molecules
• The formation of sigma and pi bonds
• The effects of delocalisation of electrons.

topic 5 & 15 - Energetics/Thermochemistry

Energetics (aka thermodynamics) is the study of energy in chemical reactions, and is central to giving us a deeper understanding of the way chemical reactions work. The topic will build on what you already know about endothermic and exothermic reactions, bringing a mathematical framework to your understanding, before (at HL) moving on to look at more advanced concepts such as free energy and entropy.

This unit will require you to do a lot of calculations and will assume your understanding of stoichiometry (moles etc), so if this is still a weakness for you, you will need to take the initiative and practice. See here for resources and things that you could use to help with this.

topic 6 & 16 - chemical kinetics

Kinetics is all about the rate at which chemical reactions happen and the factors that govern this. At SL, this means consolidating the understanding of collision theory gained at IGCSE-level, and then extending this to understand how the ‘Boltzmann distribution’ is able to explain the effects of temperature on rate in greater depth than collision theory on it’s own. At HL we develop a quantitiative framework for analysing reaction rates, learning to develop rate equations, and understanding how these give us valuable insight into the internal mechanisms behind chemical reactions.

topic 7 & 17 - Equilibrium

Equilibrium is one of the core features of many – if not most – chemical processes, and describes the way that reactions tend to end up producing a mixture containing reactants and products, rather than just the pure products. In this unit we will learn about the processes that cause equilibria to form, and will investigate how equilibrium systems respond to small changes. This is useful not only because it’s interesting, but also because it helps us to explain a lot of important phenomena regarding oxidation and reduction reactions and acids and bases.

topic 8 & 18 - Acids & bases

Acids and bases are some of the most familiar compounds in everyday life, and most people have at least a rudimentary understanding of them. In this unit we will be looking in detail at both acids and bases, looking at two different models for describing them (Bronsted-Lowry and Lewis), their chemical properties, and the pH scale which is used to measure their ‘strength’. At HL we will bring a level of quantitative rigour to our understanding and will learn how to calculate quantities such as pH, Ka and pKb and their basic counterparts, and we will investigate buffer systems.

topic 9 & 19 - REDOX Reactions

Oxidation and reduction (aka redox) reactions are those where atoms change their oxidation state, meaning they have either gained or lost electrons. This is a broad area of chemistry, and many reactions can technically be considered redox reactions. However, for the purposes of this topic we are generally talking about:

• Reactions involving metals
• Reactions in voltaic cells (batteries)
• Reactions in electrolytic cells

Topic 10 & 20 - Organic Chemistry

Organic chemistry is the study of carbon-containing compounds. It is called ‘organic’ because it used to be thought that carbon compounds only came from living things, but now we know that is not true. In this topic we will learn about a wide range of types of organic compounds, learning how to name them and some of the reactions they do. We will also look at the mechanisms for some of these reactions. At HL there is a particular focus on the fine details of isomerism, and the importance of the shape of molecules.

Topic 11 & 21 - Measurement & Data Processing & Analysis

In mathematics, when you do a sum, the answer is the answer and that is the end of the story. In science however this is different because the numbers we are putting into our calculations are uncertain. For example, you may have measured out 1.0 g of salt, but this doesn’t mean that you have exactly 1.0000000000g of salt; rather it means that you have anywhere between 0.95g and 1.05 g of salt. This in turn means that if you were using that ‘1.0 g’ of salt to do a calculation, that uncertainty in the mass would be carried through to the answer. This may seem like a weakness, but is actually one of science’s biggest strengths, as it means we can say not just what the answer is, but how certain we are about it, which is not something that history, art or economics can really do.