In chemistry A level, you’ll learn the fundamentals of physical chemistry, inorganic chemistry, and organic chemistry.
You’ll also deepen your understanding of key topics you studied at chemistry GCSE, like atomic structure and bonding. The areas you’ll study in chemistry A level are crucial in preparing you for university, equipping you with the in-depth knowledge and skills you need to complete your chemistry degree.
Chemistry A level also sets the foundation for a prosperous career in chemistry. By giving you the tools you’ll need to succeed at an entry-level chemistry-related job or at university, it will open doors to career opportunities in various industries, from environmental science and zoology, to chemical engineering and forensic chemistry.
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Physical chemistry deals with the way different types of matter are arranged, how they interact, and how they emit or absorb energy. It also looks at atoms and how they create and break bonds with each other. Part of your study of atomic structure may also involve learning about the quantum mechanical model of the atom.
Other major topics you’ll cover in physical chemistry include:
- Atomic structure: Here, you’ll study how the modern atomic model developed from John Dalton’s comprehensive theory of atoms. You’ll learn the experimental brilliance of Rutherford in his gold foil experiment that disproved J.J. Thomson’s plum pudding model, in addition to how Niels Bohr was able to propose a quantised concept of electron orbit. Finally, you’ll learn how atoms work according to Schrödinger’s wave equation, which uses mathematics to construct a wave function model for the atom.
- Amount of substance: This topic will teach you about molar mass and why one mole contains 6.02 x 1023 particles of substance (Avogadro’s number), whether a compound or element. Moles can be expressed in grams. For instance, one mole-gram of carbon-12 has 6.02 x 1023 atoms of carbon.
- Bonding: Chemical bondings, whether ionic, covalent, hydrogen bonds, or van der Waals interactions, involve the outer electrons in the valence shell or orbital. Meanwhile, the chemical and physical characteristics of substances are mainly determined by the atomic number, which is the number of protons per atom of an element. The atomic number is the identity of an element. For example, gold has 79 protons per atom. If you add three more protons to it, it becomes 82, which is lead. Gold and lead have different properties.
- Energetics: This will involve learning about enthalpy, which is the measurement of the energy involved in a chemical or physical change of substances. Enthalpy has three types: enthalpy of formation, enthalpy of sublimation, and enthalpy of reaction. Enthalpy is measured in terms of change in temperature: energy is either released or absorbed.
- Oxidation, reduction and redox equations: The oxidation state of an atom, also known as the oxidation number, is the degree of electron loss of an element in a chemical compound. It can be positive, negative or zero. When a substance loses electrons, it undergoes oxidation. When it gains electrons, it undergoes reduction. Balancing redox reactions is crucial in determining the final products of chemical reactions.
Inorganic chemistry is focused on the study of inorganic compounds and organometallic substances. When studying this at chemistry A level, you’ll learn about the properties of elements and how they interact. You’ll also learn how to predict the products of chemical reactions among inorganic compounds. Some of the the topics that are covered in inorganic chemistry include:
- Periodicity: You’ll study how the elements are arranged in the periodic table, why some elements are more reactive than others, and why certain elements are non-reactive entirely. The elements are grouped together based on columns, which indicate their families. Elements that belong to the same column have similar properties. For example, column 18 is the noble gases group, which includes helium, xenon, krypton, and several others, all of which have very low reactivity.
- Group 2, the alkaline earth metals: These include calcium, beryllium, magnesium, and radium. They’re generally shiny and silvery-white compounds, are somewhat reactive, and readily lose their two outermost electrons. You’ll learn about the trends in atomic radius, first ionisation energy, and the melting points of these elements, and how this relates to their uses. You’ll also study how they react with certain substances, and will carry out several experiments, such as mixing solutions of soluble Group 2 salts with sodium hydroxide to test the solubility of hydroxides.
- Group 7(17), the halogens: The halogens are the most reactive elements. They include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). They’re highly reactive and can be rarely found in elemental form on earth because they have seven valence electrons in their highest-energy orbitals (ns2np5). At A level, you’ll study the trends in their properties, such as electronegativity, as well as how chlorine reacts with water.
Organic chemistry is distinguished from inorganic chemistry by just one element: carbon. The versatility of carbon is owed to its ability to form chains and various types of bonds, including single, double, and triple bonds. As such, carbon is the foundation of life as we know it.
Organic chemistry, however, is not concerned with the biological chemicals inside living organisms, but rather with chemicals that are derived from organic compounds and have industrial applications, such as hydrocarbons. Here are some of the topics that you’ll study in organic chemistry at A level:
- Alkanes: These are single bonded hydrocarbons that form straight and branched chains. Their formulas can be generalised as CnH2n+2
- Halogenoalkanes: These are organic compounds that are derivatives of hydrocarbons and contain halogens
- Alkenes: These are hydrocarbons that contain double bonds, examples of which include ethylene, 1-butene, and 1-pentene. The formulas for alkenes can be generalised as CnH2n
- Alcohols: These are substances that have molecules containing a hydroxyl functional group that’s bonded to the carbon atom of an alkyl or substituted alkyl. They can be synthesised in different ways, such as fermentation
- Optical isomerism: Organic compounds that are chemically the same in terms of formula, but may behave differently because they structurally mirror images of each other
- Aldehydes and ketones: Compounds that have incorporated carbonyl functional groups, C=O. The main difference between them is the extra R group in ketones, which can be any hydrocarbon chain, as shown in the illustration below:
- Carboxylic acids and derivatives: These include amides, esters, thioesters, and acyl phosphates. They’re similar to aldehydes and ketones. The main difference is a group that contains electronegative heteroatoms. This is usually oxygen, nitrogen, or sulphur attached to the carbonyl carbon
- Aromatic chemistry: This is concerned with hydrocarbons and derivatives that have aromatic benzene rings. This area is crucial in synthesising many types of compounds, including medicines
- Amines: These compounds are derivatives of ammonia. They’re organic compounds that contain nitrogen atoms with a lone pair. Below are some examples of amines:
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