In chemistry, the law of definite proportions, sometimes called Proust's Law, states that a chemical compound always contains exactly the same proportion of elements by mass. An equivalent statement is the law of constant composition, which states that all samples of a given chemical compound have the same elemental composition by mass. For example, oxygen makes up about 8/9 of the mass of any sample of pure water, while hydrogen makes up the remaining 1/9 of the mass. Along with the law of multiple proportions, the law of definite proportions forms the basis of stoichiometry.
Read more about Law Of Definite Proportions: History, Non-stoichiometric Compounds
Famous quotes containing the words law of, law, definite and/or proportions:
“The law of nature is, do the thing, and you shall have the power: but they who do not the thing have not the power.”
—Ralph Waldo Emerson (1803–1882)
“When shot, the deer seldom drops immediately, but runs sometimes for hours, the hunter in hot pursuit. This phase, known as ‘deer running,’ develops fleet runners, particularly in deer- jacking expeditions when the law is pursuing the hunters as swiftly as the hunters are pursuing the deer.”
—For the State of Maine, U.S. public relief program (1935-1943)
“I have not the most definite designs on the future.”
—Henry David Thoreau (1817–1862)
“A ‘spasm band’ is a miscellaneous collection of a soap box, tin cans, pan tops, nails, drumsticks, and little Negro boys. When mixed in the proper proportions this results in the wildest shuffle dancing, accompanied by a bumping rhythm.”
—For the City of New Orleans, U.S. public relief program (1935-1943)