Acids and Alkali Indicators
Chemistry: Edexcel IGCSE, topic 12.1.1
Acids and Alkalis
Acids and alkalis are on the opposite ends of the pH scale. They combine to form water, which is neutral.
Acids
- Acids are substances that form hydrogen (H+) ions when they dissolve in water (aqueous solutions).
- Acids are proton donors.
Alkalis
- Alkalis are substances that form hydroxide (OH-) ions when they dissolve in water (aqueous solutions).
- Alkalis can neutralise acids.
- An alkali is a type of base. An alkali is a base that's soluble in water.
- Bases are proton acceptors.
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Measured using pH scale
- The pH scale is used to measure how acidic or alkaline a substance is.
Test yourself on Acids and Alkali Indicators
Which of these are true of acids?
Which of these are true of alkalis?
Thinking about what ions form when they dissolve in water, why does mixing an acid and an alkali create a neutral substance?