Acid-base chemistry
Study G3 Science Chemistry ions, pH and indicators, explain acid reactions and neutralisation, and apply these ideas to soil treatment and oxides.
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Before you begin
Study G3 Science Chemistry ions, pH and indicators, explain acid reactions and neutralisation, and apply these ideas to soil treatment and oxides.
Learning goals
- Describe acids and alkalis by the ions they form in water and their effect on Universal Indicator
- Compare neutral, acidic and alkaline solutions by their relative H⁺ and OH⁻ ion concentrations
- Compare neutral, acidic and alkaline solutions by their colour in Universal Indicator
- Compare neutral, acidic and alkaline solutions using the pH scale
- Describe how acids react with metals, bases and carbonates to form salts
- Describe neutralisation as hydrogen ions reacting with hydroxide ions to form water, H⁺ + OH⁻ → H₂O
- Describe how bases react with acids and with ammonium salts
- Describe why soil pH must be controlled and how calcium hydroxide treats acidic soil
- Classify oxides as acidic, basic, amphoteric or neutral from whether the element is a metal or non-metal
Syllabus statements covered
- describe the meanings of the terms acid and alkali in terms of the ions they produce in aqueous solution and their effects on Universal Indicator
- describe neutrality and relative acidity and alkalinity, in terms of — relative H+ and OH- ion concentrations,
- describe neutrality and relative acidity and alkalinity, in terms of — colour in Universal Indicator, and
- describe neutrality and relative acidity and alkalinity, in terms of — the pH scale (calculation of pH from hydrogen ion concentration is not required)
- describe the characteristic properties of acids as in reactions with metals, bases and carbonates to form salts (description of the preparation of pure salts is not required)
- describe the reaction between hydrogen ions and hydroxide ions to produce water, H+ + OH- → H2O, as neutralisation
- describe the importance of controlling the pH in soils and how excess acidity can be treated using calcium hydroxide
- describe the characteristic properties of bases in reactions with acids and with ammonium salts
- classify oxides as acidic, basic, amphoteric or neutral based on metallic/non-metallic character.
Lessons
Work through them in order.
- Acids, bases, alkalis and indicatorsUse the ions in a solution and indicator colours to classify it as acidic, neutral or alkaline.
- Acid reactions and neutralisationPredict the products of acids with metals, bases and carbonates, and explain neutralisation with ions.
- Applications and oxide behaviourChoose a treatment for acidic soil and classify oxides from how they react with acids and alkalis.
Practise and check
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