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Acids and their properties
An acid is a substance that dissociates hydrogen ions (H+) when dissolved in water.
1. Acids taste sour.
2. Acids turn blue litmus paper red.
3. Acids react with metal carbonates to produce salt, carbon dioxide and water. Carbon dioxide can be tested using limewater and it forms white precipitate in limewater.
4. Acids react with reactive metals to form salt and hydrogen gas. Hydrogen gas can be tested using a burning wooden splint. The burning splint extinguishes with a "pop" sound.
5. Acids react with bases (metal hydroxide or metal oxide) to form salt and water only. This is neutralisation reaction.
1. Acids taste sour.
2. Acids turn blue litmus paper red.
3. Acids react with metal carbonates to produce salt, carbon dioxide and water. Carbon dioxide can be tested using limewater and it forms white precipitate in limewater.
4. Acids react with reactive metals to form salt and hydrogen gas. Hydrogen gas can be tested using a burning wooden splint. The burning splint extinguishes with a "pop" sound.
5. Acids react with bases (metal hydroxide or metal oxide) to form salt and water only. This is neutralisation reaction.
More discussion on acids
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Bases and their properties
A base is a substance that react with an acid to form salt and water only. This reaction is called neutralisation.
A base can be a metal oxide or metal hydroxide.
Alkalis are bases that are soluble in water (e.g. sodium hydroxide).
1. Alkalis taste bitter.
2. Alkalis feel slippery to touch.
3. Alkalis turn red litmus paper blue.
4. A base reacts with an acid to form salt and water only by neutralisation.
5. A base reacts with ammonium salts to form salt, ammonia gas and water.
See following video which explores the reaction of a base (sodium hydroxide) with an ammonium salt (ammonium nitrate) to form salt, ammonia gas and water.
NaOH (aq) + NH4NO3 (aq) → NaNO3 (aq) + NH3 (g) + H2O (l)
A base can be a metal oxide or metal hydroxide.
Alkalis are bases that are soluble in water (e.g. sodium hydroxide).
1. Alkalis taste bitter.
2. Alkalis feel slippery to touch.
3. Alkalis turn red litmus paper blue.
4. A base reacts with an acid to form salt and water only by neutralisation.
5. A base reacts with ammonium salts to form salt, ammonia gas and water.
See following video which explores the reaction of a base (sodium hydroxide) with an ammonium salt (ammonium nitrate) to form salt, ammonia gas and water.
NaOH (aq) + NH4NO3 (aq) → NaNO3 (aq) + NH3 (g) + H2O (l)