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Oak National Academy
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Year 11
OCR
Higher

Making ammonia

I can safely produce ammonia in the laboratory.

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New
New
Year 11
OCR
Higher

Making ammonia

I can safely produce ammonia in the laboratory.

Download all resources
Share activities with pupils

Lesson details

Key learning points

  1. Ammonia can be synthesised in the lab by heating a mixture of NH₄Cl and NaOH, producing NH₃ gas and other by-products.
  2. Ammonia is an alkaline gas that reacts readily with water to form a corrosive, basic solution.
  3. Ammonia gas turns moist red litmus paper blue, indicating its alkaline nature.
  4. Ammonia gas is soluble, toxic, and has a pungent smell, requiring careful handling.
  5. Ammonia reacts with hydrogen chloride (from concentrated hydrochloric acid) to form white fumes of ammonium chloride.

Common misconception

Pupils may think ammonia is safe to handle without precautions because it's a common household chemical.

Emphasise ammonia's toxicity and the importance of using PPE and proper ventilation.

Keywords

  • Ammonia - a simple molecular substance, with the formula NH₃, is a soluble, toxic, pungent gas at room temperature.

  • Alkaline - a base that dissolves in water; these solutions have a pH greater than 7

  • Pungent - a description of a substance that has a sharply strong smell

  • Toxic - a substance that is poisonous, and can cause harm or death to living organisms

  • Corrosive - a substance that causes damage by chemical action, often resulting in severe injury or destruction

Take care when demonstrating or completing practical work with ammonia gas. Ensure you have practised in advance, and completed a full risk assessment. Ensure a well ventilated area, or use fume cupboards.
Teacher tip

Equipment

ammonium chloride, calcium hydroxide, calcium oxide, concentrated hydrochloric acid, red and blue litmus paper, UI paper, access to fume cupboard, nitrile gloves, demo setup shown in slides

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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Starter quiz

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6 Questions

Q1.
Which of the following statements about bases are correct?
Bases have a pH less than 7.
All bases are soluble in water.
Correct answer: A strong base has a pH of 14.
Q2.
Nitrogen can be found in Group 5, period 2 of the periodic table. What does this tell you about the electron configuration in nitrogen?
Correct answer: Each atom has 2 shells of electrons.
Each atom has 5 shells of electrons.
Correct answer: Each atom's outer shell contains 5 electrons.
Each atom's outer shell contains 2 electrons.
Q3.
What term do we use in science to show that a substance is dissolved in water?
Correct Answer: aqueous
Q4.
Ammonium chloride has the formula NH₄Cl. Which of the following statements about the formula for ammonium chloride are correct?
Correct answer: The ratio of hydrogen to chlorine is 4 : 1.
Correct answer: The ratio of nitrogen to chlorine is 1 : 1.
The ratio of hydrogen to nitrogen is 1 : 4.
The ratio of chlorine to nitrogen is 1 : 4.
Q5.
What type of bonding forms an ammonia, NH₃, molecule?
Correct Answer: covalent bonding, covalent
Q6.
Which of the following are examples of physical properties of a substance?
Correct answer: Melting point
Correct answer: Electrical conductivity
pH
Reaction with oxygen

Exit quiz

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6 Questions

Q1.
Match the following terms to the correct definition.
Correct Answer:Toxic,A poisonous substance that causes harm or death to living organisms.

A poisonous substance that causes harm or death to living organisms.

Correct Answer:Corrosive,A substance that causes damage by chemical action.

A substance that causes damage by chemical action.

Correct Answer:Alkaline,A base soluble in water producing a solution with a pH greater than 7.

A base soluble in water producing a solution with a pH greater than 7.

Q2.
Hydrogen chloride reacts with ammonia to form ammonium chloride, NH₄Cl. Which of the following chemical equations shows this reaction correctly?
Correct answer: HCl + NH₃ → NH₄Cl
NH₄Cl → HCl + NH₃
NH₄Cl + NH₃ → HCl
Q3.
What does this hazard warning symbol tell you about a substance?
An image in a quiz
Correct answer: It is corrosive.
It is toxic.
It is explosive.
It is flammable.
It is a moderate hazard.
Q4.
A student places a piece of damp red litmus paper in ammonia gas. Which of the following statements about this activity are correct?
Correct answer: The litmus paper will turn blue.
Correct answer: Ammonia is an alkaline gas.
The litmus paper will remain red.
Ammonia is an acidic gas.
Q5.
Which of the following are examples of chemical properties of ammonia?
Ammonia is a colourless gas at room temperature.
Correct answer: Ammonia gas has an approximate pH of 11.
The boiling point of ammonia is -33 °C.
Correct answer: Ammonia neutralises nitric acid.
Q6.
Ammonia is a toxic gas. What control measures, or precautions, can be taken in a lab to limit the risk?
Correct answer: Use a fume cupboard.
Correct answer: Use a well ventilated area.
Wash in plenty of water.
Remove contaminated clothing.
Wear safety goggles.