CHEM 162 FINAL EXAM QUESTIONS
WITH CORRECT ANSWERS
The dissolution of water in octane (C8H18) is prevented by __________. - Correct
Answers -hydrogen bonding between water molecules
Hydration is a specific example of the phenomenon known generally as __________ -
Correct Answers -solvation
The dissolution of gases in water is virtually always exothermic because __________. -
Correct Answers -one of the two endothermic steps (separation of solute particles) in
the solution-formation process is unnecessary
The phrase "like dissolves like" refers to the fact that __________. - Correct Answers -
polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes
Why doe gases spontaneously mix (unless unrestrained)? - Correct Answers -because
with gases intermolecular forces are too weak to restrain the molecules
Pairs of liquids that mix in all proportions, such as acetone and water, are __________,
whereas those that do not dissolve in one another are _________. - Correct Answers -
1. miscible
2. immiscible
Why does soda become less bubbly when outside of the fridge? - Correct Answers -As
carbonated beverages are allowed to warm, the solubility of CO2 decreases, and
CO2(g) escapes from the solution. This is because the solubility of gases in water
decreases with increasing temperature
Why do bubbles form on the inside wall of a cooking pot when water is heated
on the stove, even though the water temperature is well below the boiling point
of water? - Correct Answers -Dissolved gases become less soluble as temperature
increases, and they come out of solution, forming bubbles below the boiling point of
water.
Why does NaCl dissolve in water but not in gasoline? - Correct Answers -Solid NaCl
dissolves readily in water because the attractive solvent-solute interactions between the
polar H2O molecules and the ions are strong enough to overcome the attractive solute-
solute interactions between ions in the NaCl(s) and the attractive solvent-solvent
WITH CORRECT ANSWERS
The dissolution of water in octane (C8H18) is prevented by __________. - Correct
Answers -hydrogen bonding between water molecules
Hydration is a specific example of the phenomenon known generally as __________ -
Correct Answers -solvation
The dissolution of gases in water is virtually always exothermic because __________. -
Correct Answers -one of the two endothermic steps (separation of solute particles) in
the solution-formation process is unnecessary
The phrase "like dissolves like" refers to the fact that __________. - Correct Answers -
polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes
Why doe gases spontaneously mix (unless unrestrained)? - Correct Answers -because
with gases intermolecular forces are too weak to restrain the molecules
Pairs of liquids that mix in all proportions, such as acetone and water, are __________,
whereas those that do not dissolve in one another are _________. - Correct Answers -
1. miscible
2. immiscible
Why does soda become less bubbly when outside of the fridge? - Correct Answers -As
carbonated beverages are allowed to warm, the solubility of CO2 decreases, and
CO2(g) escapes from the solution. This is because the solubility of gases in water
decreases with increasing temperature
Why do bubbles form on the inside wall of a cooking pot when water is heated
on the stove, even though the water temperature is well below the boiling point
of water? - Correct Answers -Dissolved gases become less soluble as temperature
increases, and they come out of solution, forming bubbles below the boiling point of
water.
Why does NaCl dissolve in water but not in gasoline? - Correct Answers -Solid NaCl
dissolves readily in water because the attractive solvent-solute interactions between the
polar H2O molecules and the ions are strong enough to overcome the attractive solute-
solute interactions between ions in the NaCl(s) and the attractive solvent-solvent
