Chapter 16.3 Test

Question 1

What is another name for external bonds?

Answer 1

Intermolecular forces

Question 2

What is the scientific name for external bonds?

Answer 2

Van der Waals forces

Question 3

What are Van der Waals forces

Answer 3

• weakest of all bond types

- bonds between molecules

Question 4

What do Van der Waals forces determine?

Answer 4

Properties of molecular compounds such as boiling point or freezing point.

Question 5

What are the three types of Van der Waals forces?

Answer 5

• Dipole-Dipole Interaction
• Hydrogen Bond
• London Dispersion Forces

Question 6

What is a Dipole-Dipole Interaction?

Answer 6

Attraction between 2 polar molecules.

Question 7

Why do dipole-dipole forces occur?

Answer 7

Because of the opposite or partial charges on their neighboring molecules

Question 8

Describe what a dipole interaction looks like.

Answer 8

Two polar molecules that have opposite partial charges attracting to each other.

Question 9

What makes polar interactions stronger or weaker?

Answer 9

The difference in electronegativity between the positive end of one molecule and the negative end of the other molecules.

Question 10

What is a hydrogen bond?

Answer 10

A type of dipole-dipole interaction, but it involves Hydrogen bonding to a very electronegative atom. It is the strongest of all the Van der Waals forces.

Question 11

What elements are usually involved in hydrogen bonds?

Answer 11

N, O, F, Cl bonded to Hydrogen

Question 12

Why is water wet?

Answer 12

Because molecules attach and bond and the bonds are strong enough to hold them together in liquid form.

Question 13

What is the main factor to look for in hydrogen bonds?

Answer 13

One exposed proton with nothing covering it. The positive charge will attract anything negative so it will pull a negative electron from another atom.

Question 14

What are London Dispersion Forces?

Answer 14

Attraction between molecules caused by random shifting of electrons within molecules.

Question 15

What are characteristics of London Dispersion forces?

Answer 15

• they are the weakest Van der Waals force

- they exist between all molecules

Question 16

What is electrons relation to molecular forces?

Answer 16

The more electrons in a molecule, the stronger the force of attraction.

Question 17

What is the relation between molecules and states of matter?

Answer 17

If molecules do not attract, they are gases, they need stronger bonds and attract together to be liquids and if they attract even stronger, they become solids.

Question 18

Are gases polar or non polar? Why?

Answer 18

non polar because they have no charge

Question 19

How do you turn gases into liquids or solids?

Answer 19

• change the conditions to very cold which slows down molecular motion and electron motions
• compress the gas to bring the molecules closer together

Question 20

What is an induced dipole?

Answer 20

When atom’s poles are created by random shifting of electrons and instantaneous charges are created.

Question 21

Why does it not rain nitrogen?

Answer 21

Instantaneous charges are caused by random shifting of electrons.

Question 22

What are the relationships between polar and non polar molecules with respect to solubility?

Answer 22

Polar dissolves polar, and vice versa

Question 23

What is a dipole moment?

Answer 23

The product of the separation of the ends of a dipole and the magnitude of the charges. It compares the charges of each molecule being bonded.

Question 24

Why does soda go flat in warm temperature?

Answer 24

Water is polar and CO2 is non polar and they will not dissolve over time.

Question 25

What causes greater forces of LDFs?

Answer 25

When more electrons are involved, it causes to form liquids and solids and

Question 26

What are the most common non polar molecules?

Answer 26

• CO2

- diatomic molecules