E*quiv"a*lent (?), a. [L.
aequivalens, -entis, p. pr. of aequivalere to
have equal power; aequus equal + valere to be strong,
be worth: cf. F. équivalent. See Equal, and
Valiant.] 1. Equal in worth or value,
force, power, effect, import, and the like; alike in significance and
value; of the same import or meaning.
For now to serve and to minister, servile and
ministerial, are terms equivalent.
South.
2. (Geom.) Equal in measure but not
admitting of superposition; -- applied to magnitudes; as, a square
may be equivalent to a triangle.
3. (Geol.) Contemporaneous in origin;
as, the equivalent strata of different countries.
E*quiv"a*lent (?), n.
1. Something equivalent; that which is equal in
value, worth, weight, or force; as, to offer an equivalent for
damage done.
He owned that, if the Test Act were repealed, the
Protestants were entitled to some equivalent. . . . During
some weeks the word equivalent, then lately imported from
France, was in the mouths of all the coffeehouse
orators.
Macaulay.
2. (Chem.) That comparative quantity
by weight of an element which possesses the same chemical value as
other elements, as determined by actual experiment and reference to
the same standard. Specifically: (a) The
comparative proportions by which one element replaces another in any
particular compound; thus, as zinc replaces hydrogen in hydrochloric
acid, their equivalents are 32.5 and 1.
(b) The combining proportion by weight of a
substance, or the number expressing this proportion, in any
particular compound; as, the equivalents of hydrogen and
oxygen in water are respectively 1 and 8, and in hydric dioxide 1 and
16.
&fist; This term was adopted by Wollaston to avoid using the
conjectural expression atomic weight, with which, however, for
a time it was practically synonymous. The attempt to limit the term
to the meaning of a universally comparative combining weight failed,
because of the possibility of several compounds of the substances by
reason of the variation in combining power which most elements
exhibit. The equivalent was really identical with, or a
multiple of submultiple of, the atomic weight.
3. (Chem.) A combining unit, whether
an atom, a radical, or a molecule; as, in acid salt two or more
equivalents of acid unite with one or more equivalents
of base.
Mechanical equivalent of heat (Physics),
the number of units of work which the unit of heat can perform;
the mechanical energy which must be expended to raise the temperature
of a unit weight of water from 0° C. to 1° C., or from
32° F. to 33° F. The term was introduced by Dr. Mayer of
Heilbronn. Its value was found by Joule to be 1390 foot pounds upon
the Centigrade, or 772 foot pounds upon the Fahrenheit, thermometric
scale, whence it is often called Joule's equivalent, and
represented by the symbol J. This is equal to 424 kilogram meters
(Centigrade scale). A more recent determination by Professor Rowland
gives the value 426.9 kilogram meters, for the latitude of
Baltimore.
E*quiv"a*lent, v. t. To make the
equivalent to; to equal; equivalence. [R.]
