alkali

[ al-kuh-lahy ]

noun

, plural al·ka·lis, al·ka·lies.

1. Chemistry.
   1. any of various bases, the hydroxides of the alkali metals and of ammonium, that neutralize acids to form salts and turn red litmus paper blue.
   2. any of various other more or less active bases, as calcium hydroxide.
   3. (not in technical use) an alkali metal.
   4. Obsolete. any of various other compounds, as the carbonates of sodium and potassium.
2. Agriculture. a soluble mineral salt or a mixture of soluble salts, present in some soils, especially in arid regions, and detrimental to the growing of most crops.

adjective

1. Chemistry. alkaline.

alkali

/ ˈælkəˌlaɪ /

noun

1. chem a soluble base or a solution of a base
2. a soluble mineral salt that occurs in arid soils and some natural waters

alkali

/ ăl′kə-lī′ /

, Plural alkalis

1. A hydroxide of an alkali metal. The aqueous solution of alkalis is bitter, slippery, caustic, and characteristically basic in reactions.

alkali

1. A bitter, caustic mineral often found in large beds in the desert. Alkalis are bases ; two common examples are lye and ammonia.

Notes

Plants have difficulty growing in soil that is rich in alkalis.

Word History and Origins

Origin of alkali¹

1300–50; Middle English alkaly < Middle French alcali < dialectal Arabic al-qalī, variant of Arabic qily saltwort ashes

Word History and Origins

Origin of alkali¹

C14: from Medieval Latin, from Arabic al-qili the ashes (of the plant saltwort)

Example Sentences

It starts by trapping atoms—often alkali metals—in a magnetic cage, then shooting a laser at them.

From Popular-Science

For example, the far-left column contains sodium and the other so-called alkali metals.

From Science News For Students

However incidental case reports show that milk-alkali syndrome still pops up from time-to-time, and often it stems from taking far too much calcium carbonate, or Tums.

From Popular-Science

Hydrolysis of polyester is a chemical reaction that occurs when polyesters decompose, it can occur with alkalis and acids, hence the need for stomach acids from a cow’s rumen to potentially dissolve plastics.

From Popular-Science

Both alkaline and alkali come from the Arabic word “al-qili.”

From Science News For Students

What appears to be ground glass is only the little crystals or small particles of alkali that have not been dissolved.

From Project Gutenberg

He was one of the men to whom alkali is a constant poison, and his lips were always cracked and bleeding.

From Project Gutenberg

He had come away in the sour mood of a thirsty man who finds an alkali spring sparkling deceptively under a rock.

From Project Gutenberg

Talpers flushed angrily, and then grinned, until his alkali-cracked lips glistened in the lamplight.

From Project Gutenberg

Now, cations other than the alkali ions are liable to interfere with tests designed for alkaline or neutral solutions.

From Project Gutenberg