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, definite and/or proportions:
“The inevitableness, the idealism, and the blessing of war, as an indispensable and stimulating law of development, must be repeatedly emphasized.”
—Friedrich Von Bernhardi (1849–1930)
“He is no more than the chief officer of the people, appointed by the laws, and circumscribed with definite powers, to assist in working the great machine of government erected for their use, and consequently subject to their superintendence.”
—Thomas Jefferson (1743–1826)
“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)