Module 4- Intermolecular Forces

Question 1

many times stronger

forces that hold molecules together

Answer 1

Intramolecular forces

Question 2

are forces that form between molecules, atoms, or ions.

Answer 2

Intermolecular forces

Question 3

Intermolecular forces are forces that form between

Answer 3

molecules,
atoms,
ions.

Question 4

responsible for the condensed phases of substances (liquid and solid form)

Solids and liquids will not exist without them.

Answer 4

Intermolecular forces

Question 5

Introduce that intermolecular forces called

Answer 5

Van der Waals forces

Question 6

Van der Waals forces named after

Answer 6

Johannes Diderik van der Waals

Question 7

Johannes van der Waals

Answer 7

did not develop the theory on the different types of intermolecular forces.

Question 8

Johannes Diderik van der Waals first one who

Answer 8

postulated them during the development of his theory on the behavior of real gases in 1873.

Question 9

Theory of Johannes Diderik van der Waals

Answer 9

behavior of real gases in 1873.

Question 10

Van der Waals forces were named after him to pay tribute to his great contribution on the study of

Answer 10

liquids and gases

Question 11

____ Fritz London, a German-born physicist (March 7, 1900 - March 30,1954) traced intermolecular forces to electron motion within molecules.

Answer 11

In 1930,

Question 12

In 1930, ____, a German-born physicist (March 7, 1900 - March 30,1954) traced intermolecular forces to electron motion within molecules.

Answer 12

Fritz London

Question 13

In 1930, Fritz London, a ____ (March 7, 1900 - March 30,1954) traced intermolecular forces to electron motion within molecules.

Answer 13

German-born physicist

Question 14

Fritz London needed ____ in order to correctly describe the forces.

Answer 14

quantum mechanics

Question 15

I. Four main types of intermolecular forces:

Answer 15

1. Ion-ion interaction
2. Dipole-dipole interaction
3. Hydrogen bonding
4. Dispersion forces also known as London forces in honor of Fritz London.

Question 16

exists between oppositely charged ions. It occurs between ionic compounds.

Answer 16

Ion-ion interaction

Question 17

Most ion-ion interaction is strong and compounds which have them have

Answer 17

high melting and boiling points

Question 18

Ions of like charges

Answer 18

repel

Question 19

opposite charges

Answer 19

attract

Question 20

The compound orients itself in such a way as to

Answer 20

minimize repulsion

Question 21

The strength of ion-ion interaction is

Answer 21

inversely proportional to the square of distance between the ions

Question 22

This is the strongest intermolecular force.

Answer 22

Ion-ion interaction

Question 23

smaller ions have _____ ion-ion interaction compared to larger ions

Answer 23

stronger

Question 24

Occurs between polar molecules.

Answer 24

Dipole- Dipole Interaction

Question 25

Dipole- Dipole Interaction Occurs between polar molecules. This is due to the

Answer 25

partial positive pole and the partial negative pole of the molecule.

Question 26

Average dipole-dipole interaction is relatively weak, around

Answer 26

4kJ/ mol

Question 27

______ is effective over a very short range.

Answer 27

Dipole- Dipole Interaction

Question 28

The strength of dipole-dipole interaction is

Answer 28

inversely proportional to distance raised to the fourth power (d4).

Question 29

Both attraction and repulsion occur _____ in Dipole- Dipole Interaction

Answer 29

simultaneously.

Question 30

is a very strong dipole-dipole interaction

Answer 30

Hydrogen bond

Question 31

____ occurs in polar molecules containing H and any one of the highly electronegative elements, in particular F, O, N.

Answer 31

Hydrogen bond

Question 32

Hydrogen bond occurs in polar molecules containing H and any one of the highly electronegative elements, in particular

Answer 32

Fluorine Oxygen Nitrogen

Question 33

Hydrogen tends to be ____ due to the strong tendencies of F, O, or N to attract the electron towards it.

Answer 33

strongly positive

Question 34

The highly electronegative elements make hydrogen

Answer 34

strongly positive

Question 35

Hydrogen bonding is responsible for the unusually _____ as compared to compounds of similar molecular weight and geometry.

Answer 35

high boiling point and melting point of water

Question 36

The ability of water to form hydrogen bonds relates to its ability to be a

Answer 36

universal solvent

Question 37

Due to its polarity, hydrogen bonds is able to _____ with ionic compounds and polar molecules.

Answer 37

dissolve (or interact)

Question 38

Hydrogen bonding is also very important to life in general as the H-bond prevents water from

Answer 38

quickly evaporating into the atmosphere

Question 39

H-bond causes the water molecules to form a _____ thereby increasing its volume. This is why ice floats on water. This prevents the water beneath from cooling down further as the ice sheet acts a protective layer. This allows marine creatures to survive in cold weather.

Answer 39

crystal lattice

Question 40

In the experiment where _____ is mixed with water, H-bonding is responsible for the decrease in volume of the solution and the production of heat.

Answer 40

methanol (CH3OH)

Question 41

is present in all molecules

Answer 41

Dispersion Forces or London Forces Dispersion force

Question 42

only force present in nonpolar molecules. It is very weak and acts in very small distances.

Answer 42

Dispersion Forces or London Forces Dispersion force

Question 43

Dispersion Forces is formed due to the attraction between the positively charged nucleus of an atom with the negatively charged electron cloud of a nearby atom. This interaction creates an _____

Answer 43

induced dipole.

Question 44

_____ happens when a normally non-polar molecule or atom temporarily becomes polar due to the influence of a nearby charged particle or dipole.

Answer 44

induced dipole

Question 45

The strength of dispersion forces is

Answer 45

inversely proportional to distance raised to the 7th power (d7).

Question 46

Without dispersion forces ______

Answer 46

substances would not be able to condense to liquid and solid phase.

Question 47

When several iodine molecules are exposed to each other, an _____ is created

Answer 47

induce dipole

Question 48

As the molecular weight of molecules increases (which also corresponds to an increased number of electrons), the _____ increases due to dispersion forces.

Answer 48

polarization

Question 49

Sometimes, _____ can be stronger than dipole-dipole interaction or even H-bonding.

Answer 49

dispersion forces