Equivalent weight (also known as gram equivalent) is a term which has been used in several contexts in chemistry. In its most general usage, it is the mass of one equivalent, that is the mass of a given substance which will:
- supply or react with one mole of hydrogen cations H+ in an acid–base reaction; or
- supply or react with one mole of electrons e
− in a redox reaction.
Equivalent weight has the dimensions and units of mass, unlike atomic weight, which is dimensionless. Equivalent weights were originally determined by experiment, but (insofar as they are still used) are now derived from molar masses. Additionally, the equivalent weight of a compound can be calculated by dividing the molecular weight by the number of positive or negative electrical charges that result from the dissolution of the compound.
Read more about Equivalent Weight: History, Use in General Chemistry, Use in Volumetric Analysis, Use in Gravimetric Analysis, Use in Polymer Chemistry
Famous quotes containing the words equivalent and/or weight:
“Distinctions drawn by the mind are not necessarily equivalent to distinctions in reality.”
—Thomas Aquinas (c. 1225–1274)
“But I saw the little-Ant men as they ran
Carrying the world’s weight of the world’s filth
And the filth in the heart of Man—
Compressed till those lusts and greeds had a greater heat
than that of the Sun.”
—Dame Edith Sitwell (1887–1964)