Gases, Liquids, Solids, and Intermolecular ForcesS.ElHajjaji/Chap6_1400_Sum2010.pdf6/25/2010 1...
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6/25/2010 1 Chapter 6 Chapter 6 Gases, Liquids, Solids, and Intermolecular Forces 6/2 Intermolecular Forces and the States of Matter Solids: The particles of a solid have fixed positions and exhibit motions of vibration. Liquids: The particles of a liquid are free to move within the confines of the liquid. Gas: The particles of a gas are far apart and move randomly and rapidly.
Transcript of Gases, Liquids, Solids, and Intermolecular ForcesS.ElHajjaji/Chap6_1400_Sum2010.pdf6/25/2010 1...
6/25/2010
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Chapter 6Chapter 6
Gases, Liquids, Solids, and Intermolecular
Forces
6/2
Intermolecular Forces and the
States of MatterSolids: The particles of a solid have
fixed positions and exhibit motions of
vibration.
Liquids: The particles of a liquid are free
to move within the confines of the
liquid.
Gas: The particles of a gas are far apart
and move randomly and rapidly.
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Intermolecular Forces and the
States of Matter
Melting point (=freezing point): The temperature at which a solid becomes a liquid.
Vaporization: The process of a liquid becoming a gas.
Boiling point: The temperature at which the particles of a liquid escape and become a gas.
6/4
Intermolecular Forces and the
States of Matter Condensation: The process by which a gas
becomes a liquid.
Freezing: The process by which a liquid becomes a solid. This occurs at the freezing point, which is the same as the melting point.
Sublimation: When a solid changes directly from the solid to the gaseous state.
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Intermolecular Forces and the
States of Matter
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Intermolecular Forces and the
States of Matter
Ionic bonds: Ionic bonds are the strongest of
forces that hold matter in the condensed states (liquids+solids).
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Intermolecular Forces and the
States of MatterDipole forces: Polar molecules exist as dipoles. These oppositely charged ends will attract each other.
solid liquid
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Intermolecular Forces and the
States of MatterHydrogen bonds: When a hydrogen atom is covalently bonded to a highly electronegative atom like nitrogen, oxygen, or fluorine (N,O,F), it can exhibit an additional polar attraction. This attraction is called a hydrogen bond.
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Intermolecular Forces and the
States of MatterDispersion forces: Nonpolar molecules exhibit a dynamic induced dipole. The strength of this force increases with molecular weight and is known as dispersion forces or London dispersion forces.
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Intermolecular Forces and the
States of MatterSolution: An intimate, homogeneous mixture of
two or more substances.
Solute: A substance that is dispersed in a solution.
Solvent: A substance doing the dissolving, usually present in greatest quantity.
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Intermolecular Forces and the
States of Matter
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Intermolecular Forces and the
States of Matter“Like dissolves like”: Solutions form most readily when both the solute and solvent have similar intermolecular forces.
oil and gasoline oil and vinegar
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Intermolecular Forces and the
States of MatterIonic substances dissolve in water through ion-dipole interactions.
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The Gas Laws
Kinetic Molecular Theory of a GasPostulates:1. The particles of a gas are in rapid constant
motion.2. The particles of a gas are tiny compared to the
distance between them.3. There is little attraction between the particles
of a gas.4. Collisions between gas molecules are perfectly
elastic.5. Temperature is a measure of the average
kinetic energy of gas molecules.
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The Gas Laws
Pressure = gas particles hitting the walls
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The Gas Laws
Boyle’s law: At constant temperature, the volume of a gas is inversely proportional to its pressure.
V α 1/P
V = a/P
PV = a
V1P1 = V2P2
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The Gas Laws
Boyle’s law: At constant temperature, the volume of a gas is inversely proportional to its pressure.
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The Gas Laws
Charles’s law: At constant pressure, the volume of a gas is directly proportional to its absolute temperature.
V α T
V = bT
V/T = b
V1/T1 = V2/T2
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The Gas Laws
Charles’s law: At constant pressure, the volume of a gas is directly proportional to its absolute temperature.
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The Gas Laws
Charles’s Law
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The Gas Laws
Avogadro’s law: At fixed temperature and pressure, the volume of a gas is directly proportional to the amount of gas.
V α n
V = cn
V/n = c
V1/n1 = V2/n2
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The Gas Laws
Ideal gas law:
PV = nRT
R = 0.0821 Kmol
atmL
•
•
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The Gas Laws
Ideal gas law:
PV = nRT
R = 0.0821 Kmol
atmL
•
•
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The Gas Laws
Standard temperature and pressure:
Standard temperature = 0 oC
Standard pressure = 1 atm
A mole of any gas at STP occupies 22.4 L
22.4 L = 28.1 cm x 28.1 cm x 28.1 cm
