Dictionary Meaning and Definition on 'Acidity'
- the property of being acidic [syn: sourness, sour]
- the taste experience when something acidic is taken into the mouth [syn: acidulousness]
- pH values below 7 [ant: alkalinity]
- Acidity \A*cid"i*ty\, n. [L. acidites, fr. acidus: cf. F.
acidit['e]. See Acid.]
The quality of being sour; sourness; tartness; sharpness to
the taste; as, the acidity of lemon juice.
Wikipedia Meaning and Definition on 'Acidity'
An acid (from the Latin acidus/acēre meaning sour) is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have pHs of less than 7, and turn blue litmus paper red. Chemicals or substances having the property of an acid are said to be acidic.
Common examples of acids include acetic acid (in vinegar), sulfuric acid (used in car batteries), and tartaric acid (used in baking). As these three examples show, acids can be solutions, liquids, or solids. Gases such as hydrogen chloride can be acids as well.
There are three common definitions for acids: the Arrhenius definition, the Brønsted-Lowry definition, and the Lewis definition. The Arrhenius definition states that acids are substances which increase the concentration of hydronium ions (H3O+) in solution. The Brønsted-Lowry definition is an expansion: an acid is a substance which can act as a proton donor. Most acids encountered in everyday life are aqueous solutions, or can be dissolved in water, and these two definitions are most relevant. The reason why pHs of acids are less than 7 is that the concentration of hydronium ions is greater than 10−7 moles per liter. Since pH is defined as the negative logarithm of the concentration of hydronium ions, acids thus have pHs of less than 7. By the Brønsted-Lowry definition, any compound which can easily be deprotonated can be considered an acid. Examples include alcohols and amines which contain O-H or N-H fragments.[See more about Acidity at Dictionary 3.0 Encyclopedia]
Words and phrases related to 'Acidity'