Chapter 2: Bond Strength, Bond Polarity, Molecular Polarity

Chem 203

How is molecular geometry determined?

By NUMBER of GROUPS (either atom or lone pair of electrons) surrounding an atom

When is molecular geometry the MOST stable?

When groups are as FAR AWAY from each other

When it comes to 3-D structures, what KIND of lines are used and what do they represent?

-Wedged line- bond in FRONT

-Dashed line- bond BEHIND plane

-Solid line- bond IN plane

When it comes to bond length/bond strength, how does the number of electrons between two nuclei influence bonds?

As electrons INCREASE between two nuclei, bonds are SHORTER and STRONGER

What is the order of INCREASING bond strength?

Single<double<triple

What is the relationship between s character percentage and bond strength?

As the percentage of s character INCREASES, bond strength INCREASES

When electronegativity is involved, what values distinct a nonpolar bond from a polar bond from an ionic bond?

-Nonpolar: <0.5

-Polar: 0.5-2

-Ionic: >2

When polar covalent bonds exist, what kind of charges are used?

-Partial + and partial -

-Bond dipole moment created

What TWO things influence molecule polarity?

-Bond POLARITY and bond ANGLES

-Polar molecules will have a NET DIPOLE moment