1 / 9

Polar Covalent Bonds

Polar Covalent Bonds. Trends in the Periodic Table and Bonding. -. -. -. -. +. +. +. +. Covalent Bonding. A covalent bond is a shared pair of electrons electrostatically attracted to the positive nuclei of two atoms. Both nuclei try to pull the electrons towards themselves .

kalea
Télécharger la présentation

Polar Covalent Bonds

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. Polar Covalent Bonds Trends in the Periodic Table and Bonding

  2. - - - - + + + + Covalent Bonding A covalent bond is a shared pair of electrons electrostatically attracted to the positive nuclei of two atoms. Both nuclei try to pull the electrons towards themselves The atoms achieve a stable outer electron arrangement (a noble gas arrangement) by sharing electrons. This is like a tug-of-war where both sides are pulling on the same object. It creates a strong bond between the two atoms.

  3. Covalent Bonding Picture a tug-of-war: If both teams pull with the same force the mid-point of the rope will not move.

  4. H H e e Pure Covalent Bond This even sharing of the rope can be compared to a pure covalent bond, where the bonding pair of electrons are held at the mid-point between the nuclei of the bonding atoms.

  5. CovalentBonding What if it was an uneven tug-of-war? The team on the right are far stronger, so will pull the rope harder and the mid-point of the rope will move to the right.

  6. Polar Covalent Bond A polar covalent bond is a bond formed when the shared pair of electrons in a covalent bond are not shared equally. This is due to different elements having different electronegativities.

  7. δ- δ+ H e e I Polar Covalent Bond e.g. Hydrogen Iodide If hydrogen iodide contained a pure covalent bond, the electrons would be shared equally as shown above. This makes iodine slightly negative and hydrogen slightly positive. This is known as a dipole. However, iodine has a higher electronegativity and pulls the bonding electrons towards itself (winning the tug-of-war)

  8. δ- δ+ C Cl Electronegativities Polar Covalent Bond In general, the electrons in a covalent bond are not equally shared. e.g. 3.0 2.5 δ- indicates where the bonding electrons are most likely to be found.

  9. C Cl 2.5 3.0 P H 2.2 2.2 O H C Cl O H 3.5 2.1 P H δ- δ+ δ- δ+ Polar Covalent Bond Consider the polarities of the following bonds: Difference Electronegativities Bond 0.5 0 1.4 Increasing Polarity Complete a similar table for C-N, C-O and P-F bonds.

More Related