Acids and bases

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Topics in acids and bases

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In chemistry, a compound could be an acid or a base. Acids and bases are very important in chemistry. They describe a large class of substances. Understanding their properties allows us to rationalize patterns that occur in chemistry.

## Contrasting properties of acids and Alkalis

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Here is a list which contrasts their properties:

* Acids turn blue litmus paper red. Bases turn red litmus paper blue.
* Acids give off H+ (Hydrogen) ions in water; bases give off OH- (Hydroxide) ions in water.
* Acids generally taste sour due to the sour H+ ion; bases taste bitter due to the OH- ion; but they may have other tastes depending on the other part of the molecule.
* Bases are usually soapy in nature.
* Acids corrode active metals ; Bases denature protein.
* Acids have a pH less than 7 ; Bases have a pH greater than 7

## Similar properties of acids and Alkalis

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Here is a list of properties that are common to both acids and bases

* When you dissolve an acid or base in water, it makes ions. This makes the water conduct electricity better.
* The stronger the acid (or base), the more ions are produced, so the conductivity of the solution increases.
* They can both conduct electricity.
* When an acid reacts with a base, a salt is formed
* They both can carry and share ions

## Things unique to acids

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Acids react with group 1 and 2 metals to generate hydrogen gas.

### Examples of common things which are acidic

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* Citrus fruits (Oranges, Lemons, Limes)
* Apples
* Pineapples
* Mangoes
* Water and soft drinks (Carbon dioxide reacts in water to form carbonic acid)
* Stomach acids
* Vinegar
* Liquid Drain cleaners containing sulfuric acid (Rooto)
* Any sour candy

## Things unique to Alkalis (bases)

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Bases feel slippery and soapy and taste bitter because they hydrolyze the fatty acid ester of the skin (saponification reaction).

### Examples of common things which are Alkalis

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* Lye
* Baking soda
* Bleach
* Ammonia, e.g. window cleaner
* Wasp's sting
* Some Drain cleaner (Drano, Red Devil)
* Tooth paste