At the end of the lesson, you should be able to:
1. Represent compounds using chemical
formulas, structural formulas, and models.
2. Give the similarities and differences between
the empirical formula and molecular formula
of a compound
• Molecular Formula
• Empirical Formula
• Structural Formula
• The molecular formula shows
the actual number of atoms of
each element present in a
compound.
• The Empirical formula is the
simplest formula for a compound
which is defined as the ratio of
subscripts
of
the
smallest
possible whole number of the
elements.
• A structural formula displays the atoms of
the molecule in the order they are bonded. It
also depicts how the atoms are bonded to one
another, for example single, double, and triple
covalent bond. Covalent bonds are shown
using lines.
Acetic Acid
C2H4O2
Ethyl alcohol
C2H6O
• Electron Dot Structural Formula
• Bond-line structural Formula
• Condensed structural Formula
• Skeletal structural Formula
• Lewis structures, also known as Lewis dot
formulas, Lewis dot structures, electron dot
structures, or Lewis electron dot structures,
are diagrams that show the bonding between
atoms of a molecule, as well as the lone pairs
of electrons that may exist in the molecule.
• Bond-line structure (bond-line
formula): A representation of molecular
structure in which covalent bonds are
represented with one line for each level of
bond order.
• Condensed structural formulas show the
order of atoms like a structural formula but
are written in a single line to save space
and make it more convenient and faster to
write out.
• Condensed structural formulas are also
helpful when showing that a group of atoms
is connected to a single atom in a
compound.
• Skeletal structure, skeletal formulas: are
a simplified way of representing organic
compounds. Instead of writing out all the
carbon and hydrogen atoms, they are
implied by corners, also called ‘vertices’, in
the structure.
What type of structural formula is
represented in the figure?
3
Write its line-bond and skeletal
structural formula.
Write its molecular formula.
What type of structural formula is presented in the figure?
Illustrate the compound in different formulas.
What type of structural formula is presented in the figure?
Illustrate the compound in different formulas.
What type of structural formula is presented in the figure?
Illustrate the compound in different formulas.
Draw the following alkanes based on the
required structural formula.
1. CH4 – Bond-line structure.
2. C2H6 – Condensed structure.
3. C3H8 – Skeletal structure.
4. C4H8 – Skeletal structure.
5. C2H6 – To Empirical Formula.