Polar Molecular Compounds

1. Polar Molecular Compounds SWBAT: Identify Polar and Nonpolar Molecules

2. Polar Covalent Bond Each side of the molecule has a small charge due to the electrons being UNEQUALLY SHARED. Cl H A dipole (two poles) has been created. Electron density diagram - more electron density around the chlorine Chlorine has a higher electronegativity than hydrogen. The “” symbol (delta) stands for small amount/change.

3. Bond Polarity in Water The bonds in the water molecule are POLAR. The molecule is ALSO ASYMMETRICAL. These TWO factors cause the MOLECULE to be polar. + H - O H H - O H O + + - + H H The water molecule is a DIPOLE - it has two oppositely charged “poles”.

4. B: Polarity of Entire Compounds - with multiple, different bonds Use EN to rate each bond in a compound Find overall shape of compound Find Net Dipole Moment: sum of all vectors Note: Molecules can have polar bonds, but overall they are not polar!!!! Opposing bond moments cancel each other out Unpaired Valence e- also influence shape

5. Non-Polar Molecules with Polar Bonds IF - The molecule is symmetrical… There is no overall polarity on the molecule. The MOLECULE IS NON-POLAR! F C F F F CF4 Eneg = 4.0 - 2.5 = 1.5 * Polar Bonds *

6. Which of the following molecules have a dipole moment? H2O, CO2, SO2, and CH4 O O S H H H O O O C H H C H dipole moment polar molecule dipole moment polar molecule no dipole moment nonpolar molecule no dipole moment nonpolar molecule 10.2

7. Identify the Polar and Nonpolar Molecules

8. Polarity of compounds: Why bother? Important for determining: Solubility Recite solubility rules! Water is a polar solvent: only polar compounds will dissolve in water Benzene: is a non-polar solute: only non-polar compounds will dissolve in benzene

9. Is a molecule polar?

10. Polar/Non-polar molecules