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6 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Group 2 oxides and hydroxides
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They are seen as bases and the react with acid to become neutralised. The reaction forms a salt and water.
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Bases
Acid Salt |
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Oxides
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React with water to form a solution of the metal hydroxide. And the PH would usually be from 10-12.
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MgO + H2O ----> Mg(OH)2 hydroxide
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Hydroxides
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Dissolve in water to form alkaline solutions. Solubility of hydroxides in water down a group increases and the resulting solution are more alkaline.
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Ca(OH)2 + aq-----> Ca2+ + 2OH-
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Carbonates
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They decompose by heat to form the metal oxide and carbon dioxide gas.
MgCO3 -------> MgO + CO2 |
Thermal decomposition
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Use of group 2 hydroxides
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Calcium hydroxide is used by farmers as lime to neutralise acid soils.
Magnesium hydroxide is used as milk of magnesia to relieve indigestion by neutralising excess acid in the stomach. |
Ca
Mg |
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Group 2
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The elements are more reactive down the group.
They are more soluble in water and resulting solutions become more alkaline down a group. Carbonated decompose at higher temperatures down a group. |
Reactivity
Decomposition Solubility |
