CH 102 Spring 2026 – Discussion Worksheet 2 Name: ________________________________________
1. Making comparisons between molecules.
a. Decane (C10H22) is a liquid at room temperature. Explain what holds these neutral molecular compounds (i.e.,
covalently-bonded) together to form a liquid. Explain.
b. When comparing the IMFs between molecules it is important for the molecules to be similar sizes. Why?
c. Water is a tiny molecule. Hexane (C6H14) is a much larger molecule. Water has higher boiling point than hexane.
Suggest an explanation for this difference. Decane (C10H22) has a higher boiling point than water. Why?
2. Liquid ethanol (CH3CH2OH) is held together by intramolecular forces and by intermolecular forces.
a. What happens when intermolecular forces are broken? What about when intramolecular forces are broken?
b. Can an ethanol molecule make a hydrogen bond with other ethanol molecules? If yes, draw the interactions.
c. List all of the intermolecular forces that will be present in a (pure) liquid sample of ethanol.
d. In a sample of pure ethanol containing N ethanol molecules: how many hydrogens can be “hydrogen bond
donors” and how many lone pairs can be “hydrogen bond acceptors”? What is the maximum number of hydrogen
bonds that can form in this pure sample of ethanol?
e. If ethanol were mixed with a water, more hydrogen bonds could form. Draw the interaction between one ethanol
molecule and as many water molecules as possible. What is the maximum number of hydrogen bonds that can
form in a sample of N ethanol molecules mixed with a very large (much, much greater than N molecules) number
of waters.
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1. Making comparisons between molecules.
a. Decane (C10H22) is a liquid at room temperature. Explain what holds these neutral molecular compounds (i.e.,
covalently-bonded) together to form a liquid. Explain.
b. When comparing the IMFs between molecules it is important for the molecules to be similar sizes. Why?
c. Water is a tiny molecule. Hexane (C6H14) is a much larger molecule. Water has higher boiling point than hexane.
Suggest an explanation for this difference. Decane (C10H22) has a higher boiling point than water. Why?
2. Liquid ethanol (CH3CH2OH) is held together by intramolecular forces and by intermolecular forces.
a. What happens when intermolecular forces are broken? What about when intramolecular forces are broken?
b. Can an ethanol molecule make a hydrogen bond with other ethanol molecules? If yes, draw the interactions.
c. List all of the intermolecular forces that will be present in a (pure) liquid sample of ethanol.
d. In a sample of pure ethanol containing N ethanol molecules: how many hydrogens can be “hydrogen bond
donors” and how many lone pairs can be “hydrogen bond acceptors”? What is the maximum number of hydrogen
bonds that can form in this pure sample of ethanol?
e. If ethanol were mixed with a water, more hydrogen bonds could form. Draw the interaction between one ethanol
molecule and as many water molecules as possible. What is the maximum number of hydrogen bonds that can
form in a sample of N ethanol molecules mixed with a very large (much, much greater than N molecules) number
of waters.
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