Polarity

Question 1

Explain the valence shell electron pair repulsion theory for H2O.

Answer 1

There are two single bonds (H) and two lone pairs of electrons around the central atom (O). This creates four regions of repulsion, and the electrons position themselves as far away as possible to minimize repulsion. This creates a V-shaped molecule for H2O.

Question 2

Why is H-F bond more polar than H-C bond?

Answer 2

The element with a higher electronegativity value will have a greater pull on electrons in the molecule, and therefore create a more polar bond with hydrogen (larger partial charges). Electronegativity increases across a row, and up a column of the periodic table. F therefore has a higher electronegativity level than C, and with have a more polar bond.

Question 3

Explain the polarity between carbon and hydrogen.

Answer 3

Electronegativity levels of C and H are too similar for a clear shift in electrons. This means there are little to no partial charges formed, and the molecule is non-polar (symmetrical).

Question 3

How does a polar bond differ from a polar molecule?

Answer 3

Polar bond- Charge distribution between two atoms in the bond is unequal.
Polar molecule- Charge distribution around a whole molecule is not symmetrical.