| 释义 |
equivalent weight
equivalent weightn. The weight of a substance that will combine with or replace one mole of hydrogen or one-half mole of oxygen. The equivalent weight is equal to the atomic weight divided by the valence.equivalent weight n (Chemistry) the weight of an element or compound that will combine with or displace 8 grams of oxygen or 1.007 97 grams of hydrogen. Also called: gram equivalent equiv′alent weight′
n. the combining power, esp. in grams (gram equivalent), of an element or compound, equivalent to hydrogen as a standard of 1.00797 or oxygen as a standard of 8; the atomic weight divided by the valence. [1925–30] Thesaurus| Noun | 1. | equivalent weight - the atomic weight of an element that has the same combining capacity as a given weight of another element; the standard is 8 for oxygencombining weight, eq, equivalentatomic mass, atomic weight, relative atomic mass - (chemistry) the mass of an atom of a chemical element expressed in atomic mass units |
equivalent weight
equivalent weight. The equivalent weight of an element or radical is equal to its atomic weightatomic weight,
mean (weighted average) of the masses of all the naturally occurring isotopes of a chemical element, as contrasted with atomic mass, which is the mass of any individual isotope. Although the first atomic weights were calculated at the beginning of the 19th cent.
..... Click the link for more information. or formula weightformula weight,
in chemistry, a quantity computed by multiplying the atomic weight (in atomic mass units) of each element in a formula by the number of atoms of that element present in the formula, and then adding all of these products together.
..... Click the link for more information. divided by the valencevalence,
combining capacity of an atom expressed as the number of single bonds the atom can form or the number of electrons an element gives up or accepts when reacting to form a compound.
..... Click the link for more information. it assumes in compounds. The unit of equivalent weight is the atomic mass unitatomic mass unit
or amu,
in chemistry and physics, unit defined as exactly 1-12 the mass of an atom of carbon-12, the isotope of carbon with six protons and six neutrons in its nucleus. One amu is equal to approximately 1.66 × 10−24 grams.
..... Click the link for more information. ; the amount of a substance in grams numerically equal to the equivalent weight is called a gram equivalent. Hydrogen has atomic weight 1.008 (rounded to three decimal places) and always assumes valence 1 in compounds, so its equivalent weight is 1.008. Oxygen has an atomic weight of 15.999 and always assumes valence 2 in compounds, so its equivalent weight is 7.9995. The sulfate radical (SO4) has formula weight 96.0636 and always has valence 2 in compounds, so its equivalent weight is 48.0318. Some elements exhibit more than one valence in forming compounds and thus have more than one equivalent weight. Iron (atomic weight 55.845) has an equivalent weight of 27.9225 in ferrous compounds (valence 2) and 18.615 in ferric compounds (valence 3). The weight proportion in which elements or radicals combine to form compounds can be determined from their equivalent weights. For example, hydrogen can combine with oxygen to form water; the weight proportion of oxygen to hydrogen in water is the same as the proportion of their equivalent weights, 7.9995 to 1.008 or 7.936 to 1; there is 1 weight of hydrogen for every 7.936 weights of oxygen, or water is about 11.2% hydrogen (by weight). Iron forms two oxides: ferrous oxide (FeO), in which there are 27.9225 weights of iron for each 7.9995 weights of oxygen, and ferric oxide (Fe2O3), in which there are 18.615 weights of iron for every 7.9995 weights of oxygen.equivalent weight[i′kwiv·ə·lənt ′wāt] (chemistry) The number of parts by weight of an element or compound which will combine with or replace, directly or indirectly, 1.008 parts by weight of hydrogen, 8.00 parts of oxygen, or the equivalent weight of any other element or compound. equivalent weight
weight [wāt] 1. heaviness; the degree to which a body is drawn toward the earth by gravity. (See also Tables of Weights and Measures in the Appendix.) Abbreviated wt.2. in statistics, the process of assigning greater importance to some observations than to others, or a mathematical factor used to apply such a process.apothecaries' weight see apothecaries' system.atomic weight the sum of the masses of the constituents of an atom, expressed in units" >atomic mass units (or daltons" >daltons), in SI units (i.e., kilograms), or as a dimensionless ratio derived by comparing the mass to the mass of an atom of carbon-12, which is taken as 12.000. Abbreviated At wt.avoirdupois weight see avoirdupois system.equivalent weight the amount of substance that combines with or displaces 8.0 g of oxygen (or 1.008 g of hydrogen), usually expressed in grams; for acid/base reactions, one equivalent donates or receives a mole of protons and the equivalent weight is the ratio of the molecular weight to the number of protons involved in the reaction. For oxidation-reduction reactions, one equivalent donates or receives a mole of electrons and the equivalent weight is the ratio of the molecular weight to the number of electrons involved in the reaction.gram molecular weight the molecular weight of a substance expressed in grams; one gram molecular weight of a molecular substance contains one mole of molecules. See also mole1.low birth weight (LBW) see under infant.molecular weight the weight of a molecule of a chemical compound as compared with the weight of an atom of carbon-12; it is equal to the sum of the weights of its constituent atoms and is dimensionless. Abbreviated Mol wt or MW. Although widely used, the term is not technically correct; relative molecular mass is preferable.very low birth weight (VLBW) see under infant.gram e·quiv·a·lent1. the weight in grams of an element that combines with or replaces 1 g of hydrogen; 2. the atomic or molecular weight in grams of an atom or group of atoms involved in a chemical reaction divided by the number of electrons donated, taken up, or shared by the atom or group of atoms in the course of that reaction; 3. the weight of a substance contained in 1 L of 1 n solution; a variant of (1). Synonym(s): combining weight, equivalent weight, equivalent (5) LegalSeeEquivalentFinancialSeeWeightAcronymsSeeeach wayequivalent weight
Related to equivalent weight: normalitySynonyms for equivalent weightnoun the atomic weight of an element that has the same combining capacity as a given weight of another elementSynonyms- combining weight
- eq
- equivalent
Related Words- atomic mass
- atomic weight
- relative atomic mass
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