MOLECULAR FORMULA

DEFINITIONS
MOLECULAR FORMULA
The molecular formula of a compound is defined as: "The formula of a compound which not only expresses the relative number of atoms of each kind but also expresses the actual number of atoms of each element present in one molecule".
Molecular formula and empirical formula of a compound are related as: MOLECULAR FORMULA = (EMPIRICAL FORMULA)n
Where "n" is an integer and is given by:
n = molecular mass of compound / Empirical formula mass of compound
Molecular formula of propane = C3H8.    Molecular formula of sugar = C12H22O11.
SYMBOL
A symbol is an abbreviation or short form for the chemical name of an element
A symbol represents only one atom of an element.
EXAMPLE:    Carbon = C, Hydrogen= H, Chlorine = Cl, Gold = Au, Silver = Ag, Sodium = Na, bismuth = Bi etc.
FORMULA
The representation of a molecule of a substance or compound in the form of symbols is called "formula".
With the help of formula we can find.    (1) Name of elements present in the molecule.    (2) Number of atoms of each element.    (3) Composition of compound.
EXAMPLE:    NH3, CO2, CaCO3, H2O, H2SO4 etc.