AS Chemistry

Welcome to the Tunnelworks AS Chemistry area.

Here you'll find one lesson, complete with an online presentation, student worksheets and detailed lesson plan. The lesson challenges students to solve a realistic engineering problem to help design, build or operate the Thames Tideway Tunnel.

After that, you can ‘dig deeper’ with follow-up ideas for more able students.

Finally, a CREST gold project is outlined, if you wish to connect your work to this well regarded science award scheme.

Content
The lesson gives students practice in calculating the enthalpy change for exothermic reactions using a real-world example and sample experimental data.

CREST Gold Award
Research project: students research the science that helps us understand why the number of sewage discharges into the River Thames has increased over time and the effect these have on river wildlife and the environment. They will discover what people think about the River Thames and create a communications activity to explain the science behind the project.

Introducing the Thames Tideway Tunnel

Watch the video to find out why we need to clean up the River Thames.

AS Science Exothermic reactions

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AS Science Exothermic reactions

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Screen 1: The Thames Tideway Tunnel will be lined with thousands of concrete segments. Concrete is made from cement and aggregates. The cement hydrates and hardens when it is mixed with water - this hydration reaction continues for years meaning the Tunnel lining will get stronger and stronger.

AS Science Exothermic reactions

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Screen 2.1: What’s the energy pathway for cement as it hydrates and hardens? Click next to reveal the energy pathway diagram.

AS Science Exothermic reactions

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Screen 2.2: The energy pathway for cement as it hydrates and hardens.

AS Science Exothermic reactions

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Screen 3.1: Click next to reveal the complete equations.

AS Science Exothermic reactions

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Screen 3.2: Click next to reveal the complete equations.

AS Science Exothermic reactions

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Screen 3.3: The complete equations.

AS Science Exothermic reactions

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Screen 4: How would you design an experiment to measure ΔHr for these hydration reactions?

A2 Science Stoichiometry and titrations

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A2 Science Stoichiometry and titrations

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Screen 1: Dissolved oxygen is vital for a healthy River Thames. When untreated sewage enters the River, this creates a ‘biological oxygen demand’. Aerobic bacteria thrive on the nutrients in the sewage, using up dissolved oxygen as they multiply.

A2 Science Stoichiometry and titrations

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Screen 2: Work out how 1 mol O2 is represented at each stage in the test so you can make the final calculation!

A2 Science Stoichiometry and titrations

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Screen 3.1: Click the next arrow to reveal how to ‘fix’ the O2.

A2 Science Stoichiometry and titrations

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Screen 3.2: Click the next arrow for Stage 2.

Science A2 Stoichiometry and titrations

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Screen 4.1: Click the next arrow to reveal how to release I2.

A2 Science Stoichiometry and titrations

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Screen 4.2: Click the next arrow to reveal how to release I2.

A2 Science Stoichiometry and titrations

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Screen 4.3: Click the next arrow for Stage 3.

A2 Science Stoichiometry and titrations

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Screen 5.1: Click the next arrow to reveal how to use titrate to measure I2.

A2 Science Stoichiometry and titrations

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Screen 5.2: Click the next arrow to review Winkler Test kits.

A2 Science Stoichiometry and titrations

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Slide 6: Use your calculations to identify the best kit. Identify features that enable a titration with good ‘resolving power’ or accuracy.