Properties & Effects of Acids
Chemistry: Cambridge International GCSE Supplement, topic 7.1.6
Acids, Bases & Salts: Properties and Effects of Acids
Acids have different effects on indicators, which identify whether they are acids or bases. Bases neutralise acids and whereas alkalis are soluble bases.
Properties of acids
- Acids turn blue litmus paper red.
- Acids change thymolphthalein from blue to colourless.
- Acids turn methyl orange indicator from orange to red.
- These colour changes show acids release hydrogen ions (H+).
Understanding bases and alkalis
- Bases are metal oxides or metal hydroxides.
- Alkalis are bases that dissolve in water.
- Alkalis release hydroxide ions (OH-) in water.
- Examples of alkalis: sodium hydroxide, potassium hydroxide.
- Bases neutralise acids to form salt and water.
Using indicators in chemistry
- Chemists use indicators like litmus to test unknown substances.
- Acids show distinct colour changes with different indicators.
- Indicators are useful for identifying acid strength and neutralisation.
- Understanding acid effects aids in safe chemical handling.
Summary of acid and base effects
- Acids change litmus red, thymolphthalein clear, and methyl orange red.
- Bases neutralise acids and can be soluble (alkalis) or insoluble.
- Indicators reveal the presence of acids or bases in solutions.
Test yourself on Properties & Effects of Acids
What type of ions do acids release when dissolved in water?