Definition
Compound of oxygen and a nonmetal. This compound reacts with bases to form salt and water. #ChemistryDefinitions
- Most oxides of non metals - form acidic oxides. (except for 3 that form neutral oxides)
- Most acidic oxides → dissolve in water to form acids. Eg: sulfur dioxide, which dissolved readily in water to form sulfurous acid. SO2(g) + H2O(l) → H2SO3(aq)
Carbonated drinks - slightly acidic - due to carbon dioxide dissolved in them. Carbon dioxide is added to give ‘fizz’ to drinks
Physical properties of acidic oxides Acidic oxides are oxides of non metals, these compounds are covalent substances. Most acidic oxides - covalent substances with a simple covalent structure. Some acidic oxides have a giant covalent structure - silicon dioxide.
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Most have low melting and boiling points. Commonly exist as gas at R.T.P but some exist as solids, e.g. P4O10. Some have high melting and boiling points. Natural physical state at R.T.P is solid
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Most acidic oxides are soluble in water. General equation: water soluble acidic oxide (s org) + water (l) → aqueous solution of acid (aq)
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Poor conductors of electricity in solid, liquid and gaseous states. Water soluble acidic oxides dissolved in water - produce aqueous solutions of acid - which are good conductors of electricity.
Chemical properties
Acidic oxides dissolve in water to produce aqueous solutions of acids → acidic oxides have similar chemical properties to acids.
General equation:
- acidic oxide + alkali → salt + water
- Acidic oxide + basic oxide → salt
| Acidic oxide | formula | Physical state | Acid produced in water | |
| name | formula | |||
| Carbon dioxide | CO2 | gas | Carbonic acid | H2CO3 |
| Sulfur trioxide | SO3 | gas | Sulfuric acid | H2SO4 |
| phosphorus(v) oxide | P4O10 | solid | Phosphoric acid | H3PO4 |
| Sulfur dioxide | SO2 | Gas | Sulfurous acid | H2SO3 |
| Nitrogen dioxide | NO2 | gas | Nitric acid | HNO3 |
Acidic oxides - do not react with acids.
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