College Board · AP Chemistry
AP Chemistry: Intermolecular Forces and Properties — Practice Questions & Answers
Intermolecular forces, states of matter, gas laws, kinetic theory, solutions, separations, and spectroscopy in AP Chemistry Unit 3.
576 practice questions available for this unit — here are 10 with full answers and explanations.
Start an interactive quiz on Intermolecular Forces and Properties →
Practice questions with answers
1
Multiple choice · Easy
Which intermolecular force is present in ALL molecules, whether polar or nonpolar?
- London dispersion forces
- Hydrogen bonding
- Dipole-dipole forces
- Ionic bonding
Tap an answer to check it.
WhyLondon dispersion forces arise from temporary instantaneous dipoles and exist between all molecules and atoms, regardless of polarity.
2
Multiple choice · Easy
Hydrogen bonding can occur when hydrogen is directly bonded to which of the following elements?
- Fluorine
- Carbon
- Sulfur
- Chlorine
Tap an answer to check it.
WhyHydrogen bonding requires H bonded to a highly electronegative atom: nitrogen, oxygen, or fluorine.
3
Multiple choice · Easy
According to the ideal gas law PV=nRT, if temperature increases while volume and moles are held constant, what happens to the pressure?
- Pressure increases
- Pressure decreases
- Pressure stays the same
- Pressure drops to zero
Tap an answer to check it.
WhyWith V and n constant, P is directly proportional to T, so increasing temperature increases pressure.
4
Multiple choice · Easy
Which state of matter has both a definite volume and a definite shape due to strong particle interactions?
Tap an answer to check it.
WhySolids have particles in fixed positions, giving them both a definite volume and a definite shape.
5
Multiple choice · Easy
In the kinetic molecular theory of ideal gases, the average kinetic energy of the gas particles depends only on which quantity?
- Absolute temperature
- Pressure
- Volume
- Molar mass
Tap an answer to check it.
WhyAverage kinetic energy of an ideal gas is directly proportional to the absolute (Kelvin) temperature only.
6
Fill in the blank · Easy
Molarity is defined as the number of moles of solute divided by the volume of solution in .
Answer:
liters / L / litres
WhyMolarity (M) has units of mol/L, so the volume must be expressed in liters.
7
Multiple choice · Medium
Which of the following liquids is expected to have the highest boiling point?
Tap an answer to check it.
WhyH2O exhibits strong hydrogen bonding, giving it the highest boiling point among these similar-sized molecules.
8
Multiple choice · Medium
How many moles of gas are present in a 4.0 L container at 2.0 atm and 300. K? (Use R = 0.0821 L*atm/(mol*K))
- 0.32 mol
- 0.65 mol
- 1.6 mol
- 3.2 mol
Tap an answer to check it.
Whyn = PV/(RT) = (2.0)(4.0)/((0.0821)(300.)) = 8.0/24.63 = 0.32 mol.
9
Multiple choice · Medium
What is the molarity of a solution made by dissolving 0.50 mol of NaCl in enough water to make 250 mL of solution?
- 2.0 mol/L
- 0.50 mol/L
- 1.0 mol/L
- 0.13 mol/L
Tap an answer to check it.
WhyM = mol/L = 0.50 mol / 0.250 L = 2.0 mol/L.
10
Multiple choice · Medium
Among the nonpolar molecules CH4, C2H6, C3H8, and C4H10, which has the strongest London dispersion forces?
Tap an answer to check it.
WhyC4H10 has the largest molar mass and most electrons, giving it the greatest polarizability and strongest dispersion forces.
Key terms in Intermolecular Forces and Properties
Intermolecular force: An attractive interaction acting between separate molecules or particles rather than within them.
Intramolecular force: A bonding force that holds atoms together inside a single molecule, such as a covalent bond.
London dispersion force: A weak attraction caused by temporary, instantaneous dipoles arising from fluctuating electron distributions.
Instantaneous dipole: A momentary uneven distribution of electrons that briefly gives a nonpolar particle a positive and negative end.
Induced dipole: A temporary dipole created in a particle when a nearby charge or dipole distorts its electron cloud.
Polarizability: The ease with which a particle's electron cloud can be distorted to form a temporary dipole.
Dipole-dipole force: An attraction between the oppositely charged ends of two permanent polar molecules.
Permanent dipole: A lasting separation of partial positive and partial negative charge within a polar molecule.
See the full study notes and flashcards for this unit.
Practise other AP Chemistry units