Assignment: Back to Petroleum Intermolecular Forces (IMFs) · 2018. 9. 9. · 1. weak and the vapor pressure is low weak and the vapor pressure is high 3. strong and the vapor pressure

Name: _____________________________ Date: ___________________________

Intermolecular Forces (IMFs) Homework Unit 8 - Topic 5

Back to Petroleum

Based on your previous learning about fractional distillation and your understanding of intermolecular forces, answer the following questions:

1. State the trend between the boiling point of the hydrocarbons contained in the crude oil and the number of carbon atoms in these molecules. ____________________ _______________________________ _______________________________ _______________________________ _______________________________ _______________________________ _______________________________ _______________________________

2. Describe the relationship between the strength of the intermolecular forces and the number of carbon atoms in the different hydrocarbon molecules. _________________________________________________________________________________ ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3. Explain how the strength of intermolecular forces affects the boiling point of a substance. ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

4. Are the compounds refined in a fractionating tower typically polar or non-polar molecules? Give evidence of your answer. _____________________________________________________ ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Regents & IB Chemistry 11 Unit 8, Topic 5: IMFs

Assignment: Back to Petroleum

Based on your previous learning about fractional distillation and your understanding of intermolecular forces, answer the following questions:

1. State the trend between the boiling point of the hydrocarbons contained in the crude oil and the number of carbon atoms in these molecules. 2. Describe the relationship between the strength of the intermolecular forces and the number of carbon atoms in the different hydrocarbon molecules. 3. Explain how the strength of intermolecular forces affects the boiling point of a substance. 4. Are the compounds refined in a fractionating tower typically polar or nonpolar molecules? Give evidence for your answer.

Name: _____________________________ Date: ___________________________

Name the IMF’s

Determine the type of intermolecular force that would hold the molecules of these pure substances together. You’ll need to determine if the compound is ionic or molecular (covalent), then draw the molecule to determine if it’s shape makes it polar or non-polar. Lastly, decide if the IMFs are VanDerWaals, Dipole-Dipole, Hydrogen ‘bonds’, or Ionic bonds.

1. CO2 __________________________________

2. NH3 __________________________________

3. N2 __________________________________

4. PCl3 __________________________________

5. CaCl2 __________________________________

6. Can you have a polar molecule with non-polar bonds in it? Use PH3 to explain your answer. ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

7. Can you have a non-polar molecule with polar bonds in it? Use CCl4 to explain your answer. ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________


Name: _____________________________ Date: ___________________________

1. Based on Reference Table H, which sample has the highest vapor pressure?

1. water at 20˚C 2. water at 80˚C 3. ethanol at 50˚C 4. ethanol at 65˚C

2. Compared to the boiling point of H2S, the boiling point of H2O is relatively high. Which type of intermolecular force causes this difference?

1. dipole-dipole 2. hydrogen 3. VanDerWaal’s 4. covalent

3. Which structural formula represents a dipole?

! 4. Which electron dot structure represents a

non-polar molecule?

!

5. Which type of bonding accounts for the unusually high boiling point of water?

1. ionic bonding 2. covalent bonding 3. hydrogen bonding 4. metallic bonding

6. Which electron dot formula represents a polar molecule?

!

7. Which sample of water has the lowest vapor pressure?

1. 100 mL at 50˚C 2. 200 mL at 30˚C 3. 300 mL at 40˚C 4. 400 mL at 20˚C

8. As ice melts at standard pressure, its temperature remains at 0˚C until it has completely melting. Its potential energy

1. decreases, while the intermolecular forces decrease in strength

2. increases, while the intermolecular forces decrease in strength

3. decreases, while the intermolecular forces increase in strength

4. increases, while the intermolecular forces increase in strength

9. In a substance that sublimes, the intermolecular forces of attraction are

1. weak and the vapor pressure is low 2. weak and the vapor pressure is high 3. strong and the vapor pressure is low 4. strong and the vapor pressure is high

Assignment: IMFs Drill

1. Based on Reference Table H, which sample has

the highest vapor pressure?

1. water at 20°C

2. water at 80°C

3. ethanol at 50°C

4. ethanol at 65°C

2. Compared to the boiling point of H2S, the boiling

point of H2O is relatively high. Which type of

intermolecular force causes this difference?

1. dipole-dipole

2. hydrogen

3. vanderWaal’s

4. covalent


4. Which electron-dot structure represents a non-

polar molecule?

5. Which type of bonding accounts for the unusually

high boiling point of water?

1. ionic bonding

2. covalent bonding

3. hydrogen bonding

6. Which electron-dot formula represents a polar

molecule?

7. Which sample of water has the lowest vapor

pressure?

1. 100 mL at 50°C

2. 200 mL at 30°C

3. 300 mL at 40°C

4. 400 mL at 20°C

8. As ice melts at standard pressure, its temperature

remains at 0°C until it has completely melted. Its

potential energy

1. decreases, while the intermolecular forces

decrease in strength

2. increases, while the intermolecular forces



increase in strength



9. In a substance that sublimes, the intermolecular

forces of attraction are

1. weak and the vapor pressure is low

2. weak and the vapor pressure is high

3. strong and the vapor pressure is low

4. strong and the vapor pressure is high




1. water at 20°C

2. water at 80°C

3. ethanol at 50°C

4. ethanol at 65°C




1. dipole-dipole

2. hydrogen

3. vanderWaal’s

4. covalent



polar molecule?



1. ionic bonding

2. covalent bonding

3. hydrogen bonding


molecule?


pressure?

1. 100 mL at 50°C

2. 200 mL at 30°C

3. 300 mL at 40°C

4. 400 mL at 20°C



potential energy


















1. water at 20°C

2. water at 80°C

3. ethanol at 50°C

4. ethanol at 65°C




1. dipole-dipole

2. hydrogen

3. vanderWaal’s

4. covalent



polar molecule?



1. ionic bonding

2. covalent bonding

3. hydrogen bonding


molecule?


pressure?

1. 100 mL at 50°C

2. 200 mL at 30°C

3. 300 mL at 40°C

4. 400 mL at 20°C



potential energy
















Name: _____________________________ Date: ___________________________

Hydrogen Bonds

Refer to the graph to the right, which shows the boiling points of hydrogen-Group 16 compounds.

1. What do you notice about the predicted boiling point of water as compared to its actual boiling point? _________________________________ _________________________________ _________________________________ _________________________________

2. Draw the Lewis structures for H2O, H2S, H2Se, and H2Te below:

3. What do all the Lewis Structures have in common? __________________________________ ____________________________________________________________________________________________________________________________________________________________________

4. If all the molecules have the same structure, why do they behave so differently? (Why are their physical properties / boiling points so different?) _______________________________ ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

5. What is different about the IMFs of the H2O molecule versus the IMFs of the H2S, H2Se, and H2Te molecules? ________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________

6. Label the polar covalent bonds and the hydrogen ‘bonds’ in the diagram below.

!

Assignment: Hydrogen “Bonds”

Refer to the graph to the right, which shows the

boiling points of hydrogen/group 16

compounds.

1. What do you notice about the predicted

boiling point of water as compared to its actual

boiling point?

2. Draw the Lewis structures for H2O, H2S, H2Se and H2Te below:

3. What do all the Lewis Structures have in common?

4. If all the molecules have the same structure, why do they behave so differently? (ie. Why are

their physical properties/boiling points so different?)

5. What is different about the IMFs of the H2O molecule versus the IMFs of the H2S, H2Se and

H2Te molecules?

5. Label the polar covalent bonds and the hydrogen “bonds” in the diagram below.


Assignment: Hydrogen “Bonds”

Refer to the graph to the right, which shows the

boiling points of hydrogen/group 16

compounds.

1. What do you notice about the predicted

boiling point of water as compared to its actual

boiling point?

2. Draw the Lewis structures for H2O, H2S, H2Se and H2Te below:

3. What do all the Lewis Structures have in common?

4. If all the molecules have the same structure, why do they behave so differently? (ie. Why are

their physical properties/boiling points so different?)

5. What is different about the IMFs of the H2O molecule versus the IMFs of the H2S, H2Se and

H2Te molecules?

5. Label the polar covalent bonds and the hydrogen “bonds” in the diagram below.

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Assignment: Back to Petroleum Intermolecular Forces (IMFs) · 2018. 9. 9. · 1. weak and the vapor pressure is low weak and the vapor pressure is high 3. strong and the vapor pressure