1 / 18

Polarity

Polarity. Y12 Chemistry. Polarity. Having poles Opposite ends In molecules its respect to charge Covalent bonds can be either polar or non-polar. Electronegativity. The ability of an atom to attract bonding electrons to itself. Electronegativity. Every atom is neutral….

genera
Download Presentation

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 Y12 Chemistry

  2. Polarity • Having poles • Opposite ends • In molecules its respect to charge • Covalent bonds can be either polar or non-polar

  3. Electronegativity The ability of an atom to attract bonding electrons to itself

  4. Electronegativity • Every atom is neutral…. • But the positive nucleus attracts bonding electrons depending on; • The amount of positive charge on the nucleus of the atom • The radius of the atom

  5. Electronegativities Increase across a period Flourine has the highest electronegativity Increase up a group

  6. Polar Bonds • Occur because the more electronegative atom has a greater “pull” on the bonded electrons • This leads to a slightly negative charge • The other atom is slightly positive + H Cl

  7. Ionic Covalent Continuum • Calculating the electronegativity difference between two atoms will tell us if a bond is ionic, polar covalent or non polar covalent. <0.5 0.5 – 1.6 >1.6 Ionic Non polar covalent Polar covalent

  8. Dipoles • A bond which has a positive end and a negative end is said to have an electrical dipole • The direction of the dipole is from positive to negative H Cl

  9. Polar molecules • Many molecules contain more than one bond • Each bond may or may not be polar • Sometimes the dipoles will be balanced and sometimes they will form a net dipole in one direction • A molecule with a net dipole is a polar molecule

  10. Predicting polarity • Molecules with one bond are easy • If the bond is polar the molecule is polar H Cl

  11. Predicting Polarity • In molecules with more than two atoms and polar bonds, the molecule will be non-polar only if the polarities of the bonds cancel each other out C O O CO2 is non polar because the shape is symmetrical so the polar bonds cancel each other out

  12. Predicting Polarity

  13. Symmetry of shapes

  14. CCl4 • 4 C – Cl bonds • All C  Cl

  15. CHCl3 • 3 C – Cl bonds and 1 C - H • 3 C  Cl and 1 C  H

  16. NH3 • 3 N – H bonds • All N  H

  17. Construct a flow-chart to identify polar molecules using the following statements: Polar Bonds Non-polar bonds Bonded non-metal atoms identical Bonded non-metal atoms different Electronegativity difference No electronegativity difference Polar molecule Non-polar molecule Net dipole Polar bonds cancel Polar bonds don’t cancel Polar bonds asymmetrically arranged Polar bonds symmetrically arranged

More Related