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acid rain

(Encyclopedia)acid rain or acid deposition, form of precipitation (rain, snow, sleet, or hail) containing high levels of sulfuric or nitric acids (pH below 5.5–5.6). Produced when sulfur dioxide and various nitro...

rain

(Encyclopedia)rain, precipitation in liquid form. It consists of drops of water falling from clouds; if the drops are very small, they are collectively termed drizzle. Rain plays a key role in the hydrologic, or wa...

rain tree

(Encyclopedia)rain tree, also called monkeypod, a large leguminous tropical tree (Albizia saman or Samanea saman) of tropical America belonging to the family Leguminosae (pulse family), the leaves of which fold tog...

rain forest

(Encyclopedia)rain forest: see forest.

nitric acid

(Encyclopedia)nitric acid, chemical compound, HNO3, colorless, highly corrosive, poisonous liquid that gives off choking red or yellow fumes in moist air. It is miscible with water in all proportions. It forms an a...

boric acid

(Encyclopedia)boric acid, any one of the three chemical compounds, orthoboric (or boracic) acid, metaboric acid, and tetraboric (or pyroboric) acid; the term often refers simply to orthoboric acid. The acids may be...

gallic acid

(Encyclopedia)gallic acid or 3,4,5-trihydroxybenzoic acid trīˌhīdrŏkˈsēbĕnzōˈĭk [key], C6H2(OH)3CO2H, colorless crystalline organic acid found in gallnuts, sumach, tea leaves, oak bark, and many other pla...

oxalic acid

(Encyclopedia)oxalic acid ĕthˌāndīōĭk [key], HO2CCO2H, a colorless, crystalline organic carboxylic acid that melts at 189℃ with sublimation. Oxalic acid and oxalate salts are poisonous. Oxalic acid is found...

fumaric acid

(Encyclopedia)fumaric acid fyo͞omărˈĭk [key] or trans-butenedioic acid, HO2CCH=CHCO2H, unsaturated dicarboxylic acid that melts at 287℃. Maleic acid, or cis-butenedioic acid, is a geometric isomer of fumaric ...

butyric acid

(Encyclopedia)butyric acid byo͞otənōˈĭk [key], CH3CH2CH2CO2H, viscous, foul-smelling, liquid carboxylic acid; m.p. about −5℃; b.p. 163.5℃. It is miscible with water, ethanol, and ether. It is a low molec...