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Chemistry: essential concepts

Chemistry is fundamental to our modern world, touching all aspects of our lives; food, health, materials, energy and our environment. Indeed, the solutions for many of the challenges facing the world will require Chemistry as a key facilitating science. This highly interactive module provides a broad foundation in organic, inorganic, and physical chemistry. It explores organic compounds and their synthesis, spectroscopic analysis, the Periodic Table and the reactivity of metals and non-metals, bonding and molecular shape, thermodynamics and kinetics. The practical nature of chemistry will be emphasised throughout. There will be an optional, laboratory-based residential school. The cost of accommodation, meals and travel for the optional residential school is not included in the module fee.

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Module code


  • Credits measure the student workload required for the successful completion of a module or qualification.
  • One credit represents about 10 hours of study over the duration of the course.
  • You are awarded credits after you have successfully completed a module.
  • For example, if you study a 60-credit module and successfully pass it, you will be awarded 60 credits.
Study level
Across the UK, there are two parallel frameworks for higher education qualifications, the Framework for Higher Education Qualifications in England, Northern Ireland and Wales (FHEQ) and the Scottish Credit and Qualifications Framework (SCQF). These define a hierarchy of levels and describe the achievement expected at each level. The information provided shows how OU module levels correspond to these frameworks.
2 8 5
Study method
Distance Learning
Module cost
See Module registration
Entry requirements
See Entry requirements

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What you will study

The module is delivered entirely online. Audio, video and interactive activities are integrated throughout the module and you will need to download a free external software package.

Block 1: The periodic table
Block 1 focuses on a core concept of chemistry, the periodic table. Trends in properties of elements and their simple compounds are discussed and the predictive powers of the Periodic Table emphasised. Extraction of metals is related to their chemical reactivity and the chemistry of group 1 and 17 elements is given in more detail. In this block you will go on to consider Lewis structures and the prediction of molecular shape.

Block 2: Chemical bonding
Block 2 introduces atomic and molecular orbitals, as you take a pictorial approach to quantum mechanics rather than being purely mathematical.

Block 3: Organic molecules
Block 3 looks at the structure of organic molecules, their stereochemistry and includes an introduction to organic nomenclature. Videos and interactive diagrams are used to aid your appreciation of the three-dimensional nature of the molecules. The software package will enable you to produce chemical structures electronically.

Block 4: Chemical thermodynamics and equilibrium
Block 4 discusses enthalpy, entropy and Gibbs free energy. These thermodynamic quantities are used to examine the principles of metal extraction quantitatively. The use of Ellingham diagrams is explained in this context. The Gibbs free energy is related to equilibrium constants and redox potentials. Audio instructions are provided to guide you through example calculations and some diagrams. You will also be introduced to an online chemistry data book and observe an online experiment in thermochemistry.

Block 5: Chemical kinetics
Block 5 considers the role of the rate of reaction, and introduces chemical kinetics. A web-based program for plotting and analysing graphs is introduced and is used to obtain information from experimental data. As part of this block, there is a virtual kinetics experiment.

Block 6: An introduction to organic reaction mechanisms
Block 6 introduces the functional group concept of a group of atoms within an organic molecule that display particular chemical properties, and the common reaction mechanisms of organic substitution and elimination reactions are discussed. Videos are used to illustrate what happens during such reactions at the molecular level.

Block 7: Alkenes and aromatics
Block 7 continues the examination of organic reaction mechanisms started in Block 6, with a discussion of addition reactions. This is followed by a detailed look at aromatic substitution reactions.

Block 8: Materials chemistry
Block 8 explores the arrangements of atoms in different types of solid. The concepts of lattices and unit cells are introduced. Metal structures are discussed in terms of close-packing of spheres, and this is extended to show how simple ionic structures can be built up from close-packed structures. Building on Block 4, the use of Born-Haber cycles to obtain lattice energies is explored. Close-packing of spheres and the build-up of more complex structures is demonstrated in a series of videos.

Block 9: Molecular characterisation and spectroscopic analysis
Block 9 looks at methods for separating and purifying chemical compounds, and then discusses the spectroscopic techniques used to determine the nature and structure of a compound. The techniques include UV/visible spectroscopy, infrared and Raman spectroscopy, NMR and mass spectrometry. Extensive online exercises are used to teach the use of infrared and NMR spectroscopy to identify molecules.

Block 10: Introduction to first row transition elements
Block 10 introduces you to the chemistry of the transition elements. The role of d orbitals in determining the properties of these elements and their compounds is explored and a simple orbital theory, crystal field theory, which can account for a number of these properties, is introduced. Many of the reactions studied are illustrated by video sequences.

Block 11: Carbonyl and organometallic chemistry
Block 11 expands your knowledge of organic reactions by introducing the chemistry of carbonyl compounds and organometallic compounds. An important organometallic reaction is synthesis using a Grignard reaction and there is a video of an example of this.

Block 12: Organic synthesis
Block 12 pursues possible strategies for synthesising organic compounds, particularly those of interest to the pharmaceutical and related industries. You learn how to plan a set of reactions that will lead to a desired product; for example, the compound responsible for the scent of a flower. The importance of overall yield reaction and the cost of starting materials are emphasised. A video showing how the principles of retrosynthetic analysis can be applied to the production of Tamiflu® forms part of this block.

Block 13: Main-group chemistry
Block 13 returns to the chemistry of the main-group elements which was introduced in Block 1. Water in rivers, streams, ponds, lakes, the water from taps and even bottled water can contain a variety of inorganic species ranging from the beneficial to the toxic. This block explores the chemistry of these species and of some of the elements they contain. Finally ways of undertaking chemical reactions in a more environmentally friendly way are discussed.

Teaching and assessment

Support from your tutor

Throughout your module studies, you’ll get help and support from your assigned module tutor. They’ll help you by:

  • Marking your assignments (TMAs) and providing detailed feedback for you to improve.
  • Guiding you to additional learning resources.
  • Providing individual guidance, whether that’s for general study skills or specific module content.
  • Facilitating online discussions between your fellow students, in the dedicated module and tutor group forums.

Module tutors also run online tutorials throughout the module. Where possible, recordings of online tutorials will be made available to students. While these tutorials won’t be compulsory for you to complete the module, you’re strongly encouraged to take part.


The assessment details for this module can be found in the facts box.

Residential school

We usually offer an optional 2.5-day laboratory school in Milton Keynes - Laboratory skills - chemistry (SS021).

The optional laboratory school would come at an additional cost. However, we’re not yet able to confirm if this face-to-face event will be offered to students starting in October 2022. The most recent additional cost was £235.

We will update this page as soon as we have more information.

Future availability

Chemistry: essential concepts (S215) starts once a year – in October.

This page describes the module that will start in October 2023.

We expect it to start for the last time in October 2023.


As a student of The Open University, you should be aware of the content of the academic regulations which are available on our Student Policies and Regulations website.

    Course work includes:

    6 Tutor-marked assignments (TMAs)
    No residential school

    Entry requirements

    This is an OU Level 2 module: you need to have a good knowledge of the subject area through either Level 1 study with the OU or equivalent study at another university.

    You must be familiar with the chemistry and mathematical content in the OU Level 1 modules Questions in science  (S111) and Science: concepts and practice  (S112).

    Check you’re ready for Chemistry: essential concepts  (S215) with our self-assessed quiz.

    If you’re still not sure you’re ready, talk to an adviser.


    Start End Fee
    - - -

    No current presentation - see Future availability

    This module is expected to start for the last time in October 2023.

    Additional Costs

    Study costs

    There may be extra costs on top of the tuition fee, such as set books, a computer and internet access.

    If your income is not more than £25,000 or you are in receipt of a qualifying benefit, you might be eligible for help with some of these costs after your module has started.

    Field school/laboratory school

    This module has an optional field school/laboratory school. You must pay an additional charge for tuition, accommodation and meals (see module details for further information). You must also pay for your travel to and from the venue.

    Due to the ongoing pandemic, we may replace face-to-face events with online alternatives.

    Ways to pay for this module

    Open University Student Budget Account

    The Open University Student Budget Accounts Ltd (OUSBA) offers a convenient 'pay as you go' option to pay your OU fees, which is a secure, quick and easy way to pay. Please note that The Open University works exclusively with OUSBA and is not able to offer you credit facilities from any other provider. All credit is subject to status and proof that you can afford the repayments.

    You pay the OU through OUSBA in one of the following ways:

    • Register now, pay later – OUSBA pays your module fee direct to the OU. You then repay OUSBA interest-free and in full just before your module starts. 0% APR representative. This option could give you the extra time you may need to secure the funding to repay OUSBA.
    • Pay by instalments – OUSBA calculates your monthly fee and number of instalments based on the cost of the module you are studying. APR 5.1% representative.

    Joint loan applications

    If you feel you would be unable to obtain an OUSBA loan on your own due to credit history or affordability issues, OUSBA offers the option to apply for a joint loan application with a third party. For example, your husband, wife, partner, parent, sibling or friend. In such cases, OUSBA will be required to carry out additional affordability checks separately and/or collectively for both joint applicants who will be jointly and severally liable for loan repayments.

    As additional affordability checks are required when processing joint loan applications, unfortunately, an instant decision cannot be given. On average the processing time for a joint loan application is five working days from receipt of the required documentation.

    Read more about Open University Student Budget Accounts (OUSBA).  

    Employer sponsorship

    Studying with The Open University can boost your employability. OU courses are recognised and respected by employers for their excellence and the commitment they take to complete. They also value the skills that students learn and can apply in the workplace.

    More than one in ten OU students are sponsored by their employer, and over 30,000 employers have used the OU to develop staff so far. If the module you’ve chosen is geared towards your job or developing your career, you could approach your employer to see if they will sponsor you by paying some or all of the fees. 

    • Your employer just needs to complete a simple form to confirm how much they will be paying and we will invoice them.
    • You won’t need to get your employer to complete the form until after you’ve chosen your module.  

    Credit/debit card

    You can pay part or all of your tuition fees upfront with a debit or credit card when you register for each module. 

    We accept American Express, Mastercard, Visa and Visa Electron. 

    Mixed payments

    We know that sometimes you may want to combine payment options. For example, you may wish to pay part of your tuition fee with a debit card and pay the remainder in instalments through an Open University Student Budget Account (OUSBA).

    Please note: your permanent address/domicile will affect your fee status and therefore the fees you are charged and any financial support available to you. The fees and funding information provided here is valid for modules starting before 31 July 2023. Fees normally increase annually in line with inflation and the University's strategic approach to fees. 

    This information was provided on 03/02/2023.

    Can you study an Access module for free?

    In order to qualify you must:

    1. be resident in England
    2. have a personal income of less than £25,000 (or receive qualifying benefits)
    3. have not completed one year or more on any full-time undergraduate programme at FHEQ level 4 or above, or completed 30 credits or more of OU study

    How to apply to study an Access module for free

    Once you've started the registration process , either online or over the phone, we'll contact you about your payment options. This will include instructions on how you can apply to study for free if you are eligible.

    If you're unsure if you meet the criteria to study for free, you can check with one of our friendly advisers on +44 (0)300 303 0069 or you can request a call back.

    Not eligible to study for free?

    Don't worry! We offer a choice of flexible ways to help spread the cost of your Access module. The most popular options include:

    • monthly payments through OUSBA
    • part-time tuition fee loan (you'll need to be registered on a qualification for this option)

    To explore all the options available to you, visit Fees and Funding.

    What's included

    The module is delivered entirely online and all study material, with the exception of the chemical structure drawing package, is accessible via the module website which includes:

    • a week-by-week study planner
    • course-specific module materials
    • audio and video content
    • assignment details and submission section
    • online tutorial access.
    • on-screen experiments and remote access to laboratory instrumentation
    • extensive preparatory materials with module team support.

    You will need

    A scientific calculator.

    Computing requirements

    You’ll need broadband internet access and a desktop or laptop computer with an up-to-date version of Windows (10 or 11). Any macOS is unsuitable with this module.

    Any additional software will be provided or is generally freely available.

    To join in spoken conversations in tutorials, we recommend a wired headset (headphones/earphones with a built-in microphone).

    Our module websites comply with web standards and any modern browser is suitable for most activities.

    Our OU Study mobile app will operate on all current, supported versions of Android and iOS. It’s not available on Kindle.

    It’s also possible to access some module materials on a mobile phone, tablet device or Chromebook. However, as you may be asked to install additional software or use certain applications, you’ll also require a desktop or laptop as described above.

    If you have a disability

    The OU strives to make all aspects of study accessible to everyone and this Accessibility Statement outlines what studying S215 involves. You should use this information to inform your study preparations and any discussions with us about how we can meet your needs.

    To find out more about what kind of support and adjustments might be available, contact us or visit our Disability support website.