Difference between revisions of "Base"
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| style="height:20px; width:200px; text-align:center;" |Blood is around [[pH]] 7.4. | | style="height:20px; width:200px; text-align:center;" |Blood is around [[pH]] 7.4. | ||
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| + | ==Key Stage 4== | ||
| + | ===Meaning=== | ||
| + | A [[base]] is a [[compound]] which is able to produce [[Hydroxide Ion|OH<sup>-</sup> ions]] when [[dissolve]]d in [[water]] to form a [[solution]] with a [[pH]] greater than [[Neutral (Chemistry)|7]]. | ||
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| + | ===About Bases=== | ||
| + | : [[Base]]s are [[Ionic Compound|ionic compounds]] where there is an [[Ionic Bond|ionic bond]] between a [[metal]] and an [[Oxide]], [[Carbonate]] or [[Hydroxide]]. | ||
| + | : [[Base]]s will [[Chemical Reaction|react]] with [[acid]]s to form a [[salt]]. | ||
| + | : Some [[base]]s are [[insoluble]]. | ||
| + | : A [[soluble]] [[base]] will [[dissolve]]s in [[water]] to produce an [[alkali]] which has [[Hydroxide Ion|Hydroxide ions]] which are either donated by the [[base]] or formed by a [[Chemical Reaction|reaction]] with [[water]] to form a [[Hydroxide Ion|Hydroxide ion]]. | ||
| + | : The [[Hydroxide Ion|Hydroxide ion]]s in an [[alkali]] will donate [[electron]]s to [[Hydrogen Ion|Hydrogen ions]] to form [[water]]. This is a [[neutralisation]] [[Chemical Reaction|reaction]]. | ||
Revision as of 11:10, 4 January 2019
Contents
Key Stage 3
Meaning
A base is a metal compound with a pH greater than 7.
About Bases
- A base can be Harmful, Irritant or corrosive.
- Bases can neutralise an acid.
- Many bases are insoluble solids.
- A base can be a:
- Metal Hydroxides are soluble bases known as 'Alkalis'.
Examples
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| Drain cleaner is around pH 14. | Oven cleaner is around pH 13.5. | Toilet cleaner is around pH 12. |
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| Baking soda is around pH 9.5. | Sea water is around pH 8. | Blood is around pH 7.4. |
Key Stage 4
Meaning
A base is a compound which is able to produce OH- ions when dissolved in water to form a solution with a pH greater than 7.
About Bases
- Bases are ionic compounds where there is an ionic bond between a metal and an Oxide, Carbonate or Hydroxide.
- Bases will react with acids to form a salt.
- Some bases are insoluble.
- A soluble base will dissolves in water to produce an alkali which has Hydroxide ions which are either donated by the base or formed by a reaction with water to form a Hydroxide ion.
- The Hydroxide ions in an alkali will donate electrons to Hydrogen ions to form water. This is a neutralisation reaction.