Chemistry Unit 12 Test Review

2 electron groups, 0 lone pairs

linear, 180 degrees

3 electron groups, 0 lone pairs

trigonal planar, 120 degrees

3 electron groups, 1 lone pair

Bent, <120°

4 electron groups, 0 lone pairs

tetrahedral, 109.5 degrees

4 electron groups, 1 lone pair

trigonal pyramidal, <109.5

4 electron groups, 2 lone pairs

Bent 109.5

5 electrons groups, 0 lone pairs

trigonal bipyramidal, 90 or 120

5 electron groups, 1 lone pair

See-saw, <90° and <120°

5 electron groups, 2 lone pairs

T-structure, <90°

5 electron groups, 3 lone pairs

Linear 180

6 electron groups, 0 lone pairs

octahedral, 90 degrees

6 electron groups, 1 lone pair

square pyramidal 90

6 electron groups, 2 lone pairs

square planar, 90 degrees

How to determine if a molecule is polar

-if there are lone pairs

-if there 2 or more different elements (excluding the core element)

How to determine if a molecule is nonpolar

-if there are no lone pairs

-if there is only two elements including the core element

-dipoles in opposite directions creates even distribution of charge in the molecule

How to determine the IMF of an molecule

Covalent Network: Carbon, Silicon or silicon with carbon or oxygen

Metallic Interactions: Metals only

Ionic bonds: metals and nonmetals

Nonmetals with N, O or F bonded with H: Hydrogen bonding(LDF)

Nonmetals with polar structure: Dipole-Dipole (LDF)

Just nonmetals: LDF

What is LDF

London dispersion force and is the weakest of the IMFs and all nonmetals have this

What is Dipole-Dipole

attractive forces between the positive end of one polar molecule and the negative end of another polar molecule

What is hydrogen bonding

Hydrogen bonding is the strongest intermolecular force. it only happens when hydrogen is covalently bonded to fluorine, nitrogen or oxygen because they're very electronegative and can pull the bonding electrons away from the hydrogen. Substances with hydrogen bonding have higher melting and boiling points because of the extra energy needed to break the hydrogen bonds.

What are ionic bonds

Electrostatic attractions between cations and anions in an ionic compound. A metal bonded to a non-metal. In some cases we can compare the relative strength of ionic IMF's. Ionic IMF's increase as the charge on the ions increase.

What are metallic interactions?

It occurs when one or more metals are combined. There are a sea of valence electrons that holds the cations together.

What is a covalent network

When the number of atoms joining together is huge and the number of atoms is not fixed and a giant lattice forms containing billions of atoms

What is molar volume?

the volume occupied by one mole of a gas

Increasing IMF causes molar volume to what?

The volume decreases

Increasing IMF causes melting point/boiling point to what?

The temperature increases

What is heat of fusion/vaporization

Energy needed to undergo a phase change

Increasing IMF causes heat of fusion/vaporization to what?

increase

What is vapor pressure

the pressure exerted by a vapor over a liquid

Increasing IMF causes vapor pressure to what?

decrease

What is lattice energy

the energy required to completely separate a mole of a solid ionic compound into its gaseous ions

Increasing IMF causes lattice energy to what?

increase

What is adhesion?

An attraction between molecules of different substances

What is cohesion?

Attraction between molecules of the same substance

What is capillary action?

Spontaneous rising of a liquid in a surface area

What is surface tension?

the resistance of a liquid to an increase in its surface area

What are the metallic properties?

-Conduct electricity

-High melting point

-malleable

-ductile

-excellent heat conductors

-shiny