Lesson Plan

4. Explore making ammonia and the Haber process

KS4-17-12

Learning Outcomes

Describe the Haber process for the manufacture of ammonia and explain how the conditions for the Haber process are selected to maximise the yield of ammonia

Higher: Can describe the Haber process for the manufacture of ammonia and explain how the conditions for the Haber process are selected to maximise the yield of ammonia
Middle:
Lower:

Activities

Mission Starter - Engage

Method:

Lesson Starter: Why do you think Haber won the Nobel Prize in Chemistry in 1931?

Resources:

Lesson Starter Slide

The Story - Explore and Explain

Method:

Answer questions and take part in activities during the presentation. Stop the presentation at the relevant slides: Talk Partners; AfLs; Songs. Take part in the Choral Response Questions activity (see Assessment section) after the Keywords/Rocket Words slide.

Resources:

Presentation Sticky notes

Mission Expert - Explain

Method:

A Thames Water expert answers the question: How is Thames Water involved in fertilisers?

The chemical reaction that feeds the world - Daniel D. Dulek

Resources:

Expert Film Slide

Mission Assignment - Elaborate

Method:

Today's film show how to safely complete the Haber process in a school lab. Write down the method and learn the key stages required.

State where the raw materials in the Haber process come from.

Describe the process for manufacturing ammonia.

Write a balanced symbol equation for the manufacture of ammonia. Use this to describe the reaction in terms of reactants, products, conditions and number of moles.

Recall the following topics:

  • dynamic equilibrium
  • temperature affecting the rate of a reaction
  • pressure.

Explain how each of these affects the Haber process reaction.

Discuss the effect of the following conditions on the reaction:

  • a high temperature
  • a low temperature
  • a high pressure
  • a low pressure
  • use of a catalyst
  • no catalyst.

Resources:

Mission Assignment Slide

Handout

Mission Log - Evaluate

Method:

Quiz With their talk partners, the children are to go through the quiz at the end of the presentation and answer the questions. Formative Assessment Forms Students are to complete these forms where present. Assessment Trays Ask the children to place their Handouts, notebooks, Formative Assessment Forms, Investigation Sheets, into either the Discover tray or Explorer tray * Explain that the green tray means that the learner has understood the lesson well, and that the red tray means that the learner needs more time to practise. * use whichever colours of tray you have in stock, or prefer to use for this. Children to take interactive Assessment Quiz to test lesson comprehension.

Resources:

Quiz in presentation Formative assessment forms Assessment trays Interactive quiz

Assessment

Questions to Ask During the Lesson

Recall a source for the nitrogen and a source for the hydrogen used in the Haber process.

Teacher Mastery

The Haber process is used to manufacture ammonia, which can be used to produce nitrogen-based fertilisers.

The raw materials for the Haber process are nitrogen and hydrogen.

The purified gases are passed over a catalyst of iron at a high temperature (about 450 °C) and a high pressure (about 200 atmospheres). Some of the hydrogen and nitrogen reacts to form ammonia. The reaction is reversible so some of the ammonia produced breaks down into nitrogen and hydrogen:

nitrogen and hydrogen ⇌ Ammonia

On cooling, the ammonia liquefies and is removed. The remaining hydrogen and nitrogen are recycled.

Curriculum Fields

National Curriculum

Recall a source for the nitrogen and a source for the hydrogen used in the Haber process. (HT only) Interpret graphs of reaction conditions versus rate.

Working Scientifically Skills

Communicating the scientific rationale for investigations, including the methods used, the findings and reasoned conclusions, using paper-based and electronic reports and presentations