alkali

alkali /al·ka·li/ (al´kah-li) any of a class of compounds with pH greater than 7.0, which form soluble soaps with fatty acids, turn red litmus blue, and form soluble carbonates, e.g., hydroxides or carbonates of sodium or potassium.

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al·ka·li (lk-l)

n. pl. al·ka·lis

1. A carbonate or hydroxide of an alkali metal, the aqueous solution of which is bitter, slippery, caustic, and characteristically basic in reactions.

2. Any of various soluble mineral salts found in natural water and arid soils.

3. Alkali metal.

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alkali

[al′kəlī]

Etymology: Ar, al + galiy, wood ash

a compound with the chemical characteristics of a base. Usually used with reference to hydroxides of Group I metals and ammonium, alkalis combine with fatty acids to form soaps, turn red litmus blue, and enter into reactions with carbon dioxide that form water-soluble carbonates. See also acid, base. -alkaline, adj. alkalinity, n., alkalinize, alkalize, v.

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alkali,

n a compound able to form hydroxyl ions (OH) when dissolved in aqueous solutions. See also base.

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alkali (al´klī),

n a strong water-soluble base. A chemical substance that, in aqueous solution, undergoes dissociation, resulting in the formation of hydroxyl (OH) ions.

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alkali

any one of a class of compounds such as sodium hydroxide that form salts with acids and soaps with fats; a base, or substance capable of neutralizing acids. Other properties include a bitter taste and the ability to turn litmus paper from red to blue. Alkalis play a vital role in maintaining the normal functioning of the body chemistry. See also acid-base balance, alkaline, base.

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alkali disease

see selenium poisoning.

alkali reserve

the ability of the combined buffer systems of the blood to neutralize acid. The pH of the blood normally is slightly on the alkaline side, between 7.35 and 7.45. Since the principal buffer in the blood is bicarbonate, the alkali reserve is essentially represented by the plasma bicarbonate concentration. However, hemoglobin, phosphates and other bases also act as buffers. A lowered alkali reserve means a state of acidosis; increased reserve indicates alkalosis. Alkali reserve is measured by the combining power of carbon dioxide, which is the amount of carbon dioxide that can be bound as bicarbonate by the blood.