1 / 11

Polarity

Learn about electron affinity, electronegativity, and bond character in chemistry. Understand how polarity affects molecules and determine polar and nonpolar bonds. Practice analyzing different molecular structures to identify polarity.

leonardsmith
Télécharger la présentation

Polarity

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Polarity

  2. Electron Affinity • A measure of the tendency of an atom to accept an electron • Increases with increasing atomic number within a period • Decreases with increasing atomic number within a group

  3. Electronegativity • Electronegativity – the relative ability of an atom to attract electrons in a chemical bond • Allows us to evaluate the electron affinity of specific atoms in a compound

  4. Bond Character • A chemical bond between atoms of different elements is never completely ionic or covalent • Bond character depends on how strongly each of the bonded atoms attracts electrons

  5. Polar Covalent Bonds • Results from unequal sharing of electrons in the bond • In a covalent bond, electrons spend more time near the nucleus of the atom with the higher electronegativity

  6. Polarity • The atom that attracts electrons most strongly (has the highest electronegativity) has a slight negative charge • δ+ means partially positive • δ- means partially negative

  7. Bond Character

  8. Determining bond character • Look at HF • Electronegativity of F = 3.98 • Electronegativity of H = 2.20 • Difference: 3.98 - 2.20 = 1.78 • Electrons move towards the fluorine atom

  9. Polarity • Polarity of molecules depends on • The presence of polar bonds • The position(s) of polar bonds in the molecule (polarity is a vector quantity) • Look at H2O and BeH2

  10. Practice • Determine if the following molecules are polar • CH4 • CH2Cl2 • CHCl3 • CCl4 • CH3Cl

  11. Nonpolar Polar Polar Nonpolar Polar

More Related