Chemical Bonding & Isomers
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Transcript of Chemical Bonding & Isomers
Chemical Bonding & Isomers
Pages 181 - 191
Recall the petroleum refining….
What is this next slide a diagram of?
What are intermolecular forces?
Page 181
The larger the hydrocarbon molecules, the _______________, the intermolecular force.
The larger the hydrocarbon molecules, the STRONGER the intermolecular force.
The larger the hydrocarbon molecules, the _______________, the boiling point.
The larger the hydrocarbon molecules, the HIGHER the boiling point.
Do you remember why atoms are attracted to other atoms?
How many valence electrons does a C atom have?
Ions and Ionic bonding
From pages 32 - 34
Find Mg on the Periodic Table…
If an atom of Mg became an ion, How does its electron structure
change?What would be its charge?What would it be classified as?
If an atom of F became an ion, How its electron structure change?What would be its charge?What would it be classified as?
Chemical Bonding
Organic chemistry – study of hydrocarbons and their derivatives
Hydrocarbons – composed of carbon chains (backbone) with H atoms attached to remaining bonding sites
Chemical Bonding Electron-dot formulas
Each dot represents 1 valence e-
Dots placed between chem symbols represent electrons shared by atoms
Single covalent bond – a pair of electrons are shared between two atoms
Ex) methane CH4
Carbon has 4 valence e-
4 H each have 1 valence e-
Structural formulasA line can be used to represent a pair of
shared e- Remember – molecules are not
2-dimensional
Alkanes Alkanes - Simple hydrocarbon family
Each C forms single covalent bonds w/ 4 other atoms
Because each C atom is bonded to the maximum # of other atoms, it is said to be saturated
Alkanes
Straight-chain alkane – each C is linked to only 1 or 2 other C atoms
Straight-chain Alkanes
Alkanes
Branched-chain alkane – 1 or more C are linked to 3 or 4 other C atoms
Isomers - molecules with identical chemical formulas but different structural formulas
Ex) octane
C8H18
Page 187
Page 187
Isomers and Boiling Point
Q. Which isomer would have the lowest boiling point temperature?
Isomers and Boiling Point
A. The molecule on the right… branched shaped decreases surface area
which results in weaker intermolecular forces. This makes it easier for the molecules to evaporate.