Formulae and amounts of substance, Nomencalture and Isomerism Summary Sheet

Formulae and amounts of substance
Empirical formula: The simplest whole number ratio of the atoms of each element in a
compound (molecular formula shows actual no.of atoms of each element in one molecule of
a substance
Molar gas volume: The volume of 1mol of gas under specified conditions of temperature
and pressure (e.g. 24dm3 at 20oc and 1atm pressure)
Number of moles = gas volume
Molar gas volume
Formula of an unknown hydrocarbon
Isomerism
CXHY + (x+ y/4)02 → XC02 + y/2 H20
Structural Stereoisomerism
Percentage yield
-Chain -E-Z
Percentage yield = actual yield
-Positional -Optical
Theoretical yield (x100)
- Functional Group
Atom economy
Mass of desired product
Total mass of products (x100)


Isomerism
Structural Isomers: Molecules with the same molecular formula but a different structural
formula
Chain isomerism: In which the molecules have the same molecular formula but a different
arrangement of the atoms in the carbon chain
Positional Isomerism: In which the molecules have the same functional group but have it in
a different position in the molecule
Functional group isomerism: Which the molecules have the same molecular formula but
have the different functional groups
Geometric Isomerism
Geometric isomers: Molecules which have the same structural formula but different
arrangement of atoms due to the presence of one or more C=C bonds
-C=C restricts rotation
-If higher priority groups (highest atomic numbers) are on the same side of the C=C it is Z, if
not it is E