5.3 Study Guide Flash Cards

Question 1

What are London Dispersion forces?

Answer 1

They are the weakest intermolecular forces that are generated from temporary dipoles created when electrons in a molecule create instantaneous polar regions.

Question 2

Are London Dispersion forces present in polar, nonpolar or both kinds of molecules?

Answer 2

Both

Question 3

What are Dipole-Dipole interactions?

Answer 3

Intermolecular forces between molecules that are permanently polar.

Question 4

What does it mean for a molecule to be polar?

Answer 4

One end of the molecule has a partial negative charge and the other end of the molecule has a partial positive charge.

Question 5

What is a hydrogen bond?

Answer 5

An intermolecular force that occurs when a Hydrogen atom is bonded to a highly electronegative atom like Oxygen, Nitrogen or Florine experiences an attractive force to an electronegative atom in a nearby molecule.

Question 6

List the three intermolecular forces in order from weakest to strongest.

Answer 6

1. London Dispersion Forces 2. Dipole-Dipole Forces 3. Hydrogen Bonds

Question 7

What does the structure of a polar molecule look like?

Answer 7

Asymmetrical with an uneven distribution of electron density due to different electronegative atoms

Question 8

What does the structure of a nonpolar molecule look like?

Answer 8

Symmetrical with atoms containing similar electronegativity

Question 9

What type of intermolecular interactions can nonpolar molecules have?

Answer 9

Only London Dispersion Forces

Question 10

What determines the type of intermolecular interactions molecules can have?

Answer 10

Polarity - being polar or nonpolar determines the type of intermolecular interactions.

Question 11

What type of interactions can polar molecules have?

Answer 11

London Dispersion Forces, Dipole-Dipole and Hydrogen Bonds

Question 12

Are polar molecule soluble in water? Why?

Answer 12

Yes, the uneven electron density in polar molecules allows them to form hydrogen bonds with the water molecules

Question 13

Are nonpolar molecules soluble in water? Why?

Answer 13

No, nonpolar molecules are insoluble in water. Nonpolar molecules have an even electron density that does not facilitate hydrogen bonding with water molecules.

Question 14

Polar Covalent Bond definition

Answer 14

Bonding electrons shared unequally between two atoms

Question 15

Nonpolar Covalent Bond definition

Answer 15

Bonding electrons shared equally between two atoms

Question 16

Generally, the term polar means?

Answer 16

Opposite Ends

Question 17

EN is an abbreviation for?

Answer 17

Electronegativity

Question 18

The bigger the difference in EN the ———- the partial charges will be.

Answer 18

larger

Question 19

The higher the EN of a molecule the more —— is it.

Answer 19

Polar (Higher pull and more assymetry)

Question 20

An atom having a stronger EN in a molecule means?

Answer 20

That atom has a stronger pull on the shared electrons than the other atoms it is next to in the molecule.

Question 21

The Carbon atom in Methane (CH4) is more electronegative than the Hydrogen atoms but the molecule is symmetrical. Is Methane polar or nonpolar?

Answer 21

Nonpolar, the electrons are pulled equally by Carbon from the four Hydrogen atoms causing the symmetrical scale and causing the molecule to not end up with more electrons on one end of the molecule.

Question 22

The Nitrogen atom in Ammonia (NH4) is more electronegative than the Hydrogen atoms and the molecule is asymmetrical. Is Ammonia polar or nonpolar?

Answer 22

Polar, the share electrons are pulled more toward the Nitrogen atom and less toward the Hydrogen atoms giving the Nitrogen end a partial negative charge and the Hydrogen end a partial positive charge.

Question 23

The difference in EN of Oxygen (3.5) and Hydrogen (2.1) is and Oxygen (3.5) and Sulfur (2.5) is? Which is more polar?

Answer 23

O-H EN = 1.4 and O-S EN = 1.0; O-H is more polar because the difference in EN is larger.

Question 24

If a molecule has an O-H bond is it more soluble in water or oil?

Answer 24

Water