| slovo | definícia |
molecular formula
(encz) | molecular formula, n: |
Molecular formula
(gcide) | Formula \For"mu*la\, n.; pl. E. Formulas, L. Formul[ae].
[L., dim. of forma form, model. SeeForm, n.]
1. A prescribed or set form; an established rule; a fixed or
conventional method in which anything is to be done,
arranged, or said.
[1913 Webster]
2. (Eccl.) A written confession of faith; a formal statement
of foctrines.
[1913 Webster]
3. (Math.) A rule or principle expressed in algebraic
language; as, the binominal formula.
[1913 Webster]
4. (Med.) A prescription or recipe for the preparation of a
medicinal compound.
[1913 Webster]
5. (Chem.) A symbolic expression (by means of letters,
figures, etc.) of the constituents or constitution of a
compound.
[1913 Webster]
Note: Chemical formul[ae] consist of the abbreviations of the
names of the elements, with a small figure at the lower
right hand, to denote the number of atoms of each
element contained.
[1913 Webster]
Empirical formula (Chem.), an expression which gives the
simple proportion of the constituents; as, the empirical
formula of acetic acid is C2H4O2.
Graphic formula, Rational formula (Chem.), an expression
of the constitution, and in a limited sense of the
structure, of a compound, by the grouping of its atoms or
radicals; as, a rational formula of acetic acid is
CH3.(C:O).OH; -- called also structural formula,
constitutional formula, etc. See also the formula of
Benzene nucleus, under Benzene.
Molecular formula (Chem.), a formula indicating the
supposed molecular constitution of a compound.
[1913 Webster] |
molecular formula
(gcide) | molecular formula \mo*lec"u*lar form"u*la\, n. (Chem.)
An expression representing the composition of elements in a
chemical substance, commonly consisting of a series of
letters and numbers comprising the atomic symbols of each
element present in a compound followed by the number of atoms
of that element present in one molecule of the substance.
Thus the molecular formula for common alcohol (ethyl alcohol)
is C2H6O, meaning that each molecule contains two carbon
atoms, six hydrogen atoms, and one oxygen atom. The molecular
formula may be written to provide some indication of the
actual structure of the molecule, in which case structural
units may be written separately. Thus, ethyl alcohol can also
be written as CH3.CH2.OH or CH3-CH2-OH, in which the
period or dash between functional groups indicates a single
bond between the principle atoms of each group. This formula
shows that in ethyl alcohol, the carbon of a methyl group
(CH3-) is attached to the carbon of a methylene group
(-CH2-), which is attached to the oxygen of a hydroxyl
group (-OH). A structural formula is a graphical
depiction of the relative positions of atoms in a molecule,
and may be very complicated.
[PJC] |
molecular formula
(wn) | molecular formula
n 1: a chemical formula based on analysis and molecular weight |
| | podobné slovo | definícia |
molecular formula
(encz) | molecular formula, n: |
molecular formula
(gcide) | Formula \For"mu*la\, n.; pl. E. Formulas, L. Formul[ae].
[L., dim. of forma form, model. SeeForm, n.]
1. A prescribed or set form; an established rule; a fixed or
conventional method in which anything is to be done,
arranged, or said.
[1913 Webster]
2. (Eccl.) A written confession of faith; a formal statement
of foctrines.
[1913 Webster]
3. (Math.) A rule or principle expressed in algebraic
language; as, the binominal formula.
[1913 Webster]
4. (Med.) A prescription or recipe for the preparation of a
medicinal compound.
[1913 Webster]
5. (Chem.) A symbolic expression (by means of letters,
figures, etc.) of the constituents or constitution of a
compound.
[1913 Webster]
Note: Chemical formul[ae] consist of the abbreviations of the
names of the elements, with a small figure at the lower
right hand, to denote the number of atoms of each
element contained.
[1913 Webster]
Empirical formula (Chem.), an expression which gives the
simple proportion of the constituents; as, the empirical
formula of acetic acid is C2H4O2.
Graphic formula, Rational formula (Chem.), an expression
of the constitution, and in a limited sense of the
structure, of a compound, by the grouping of its atoms or
radicals; as, a rational formula of acetic acid is
CH3.(C:O).OH; -- called also structural formula,
constitutional formula, etc. See also the formula of
Benzene nucleus, under Benzene.
Molecular formula (Chem.), a formula indicating the
supposed molecular constitution of a compound.
[1913 Webster]molecular formula \mo*lec"u*lar form"u*la\, n. (Chem.)
An expression representing the composition of elements in a
chemical substance, commonly consisting of a series of
letters and numbers comprising the atomic symbols of each
element present in a compound followed by the number of atoms
of that element present in one molecule of the substance.
Thus the molecular formula for common alcohol (ethyl alcohol)
is C2H6O, meaning that each molecule contains two carbon
atoms, six hydrogen atoms, and one oxygen atom. The molecular
formula may be written to provide some indication of the
actual structure of the molecule, in which case structural
units may be written separately. Thus, ethyl alcohol can also
be written as CH3.CH2.OH or CH3-CH2-OH, in which the
period or dash between functional groups indicates a single
bond between the principle atoms of each group. This formula
shows that in ethyl alcohol, the carbon of a methyl group
(CH3-) is attached to the carbon of a methylene group
(-CH2-), which is attached to the oxygen of a hydroxyl
group (-OH). A structural formula is a graphical
depiction of the relative positions of atoms in a molecule,
and may be very complicated.
[PJC] |
molecular formula
(wn) | molecular formula
n 1: a chemical formula based on analysis and molecular weight |
|