Chp 8 - Molecules

Question 1

What can we say about London Dispersion forces?

Answer 1

Most common, the more electrons the stronger the dispersion force (polarization)

Question 2

What can we say about Dipole-Dipole forces?

Answer 2

Must have polar bond.

Question 3

Of the Intermolecular forces which one is the strongest & Weakest?

Answer 3

• Weakest- London Dispersion

* Strongest- Hydrogen bonding

Question 4

How can you have a hydrogen bond?

Answer 4

• Must have hydrogen
• Bound to N,O,F
• Must have lone pair

Question 5

Are C-H bonds polar?

Answer 5

They’re non polar due to near the same electronegativity.

Question 6

compounds with same IMF tend to like one another

Answer 6

H

Question 7

Measure of vapor pressure

Answer 7

Volatility

Question 8

What is vapor pressure?

Answer 8

Likeliness of substance to be gas.

Question 9

What can you say High & Low vapor pressure?

Answer 9

• High- probably in gaseous phase

* Low- High IMF

Question 10

What is the relationship about between boiling point and IMF?

Answer 10

Higher IMF = Higher Boiling Point

Question 11

Ability of of molecules to partner up and reduce surface area

Answer 11

Surface tension

Question 12

What is an ion-dipole force?

Answer 12

Forces between an ion and polar molecule.

Question 13

Measure of a fluids resistance to flow.

Answer 13

Viscosity

*water- high viscosity

Question 14

What is the relationship between viscosity and IMF?

Answer 14

Strong IMF - Strong Viscosity

Vice versa

Question 15

How many atoms is a corner atom? Edge? Face? Center?

Answer 15

• Corner- (1/8)
• Edge- (1/4)
• Face- (1/2)
• Center- (1)

Question 16

How many atoms/unit cells does a

• simple cubic have?
• Body centered?
• Face centered?

Answer 16

• 8 x (1/8) = 1
• 8 x (1/8) + 1 = 2
• 8 x (1/8) + 6 x (1/2) = 4

Question 17

Difference between syndiotactic and isotactic?

Answer 17

• syndio- alternating branch outs

* iso- same branch outs