Chemistry for Changing Times 12 th Edition Hill and Kolb Chapter 6 Gases, Liquids, Solids, and Intermolecular Forces John Singer Jackson Community College, Jackson, MI
Dec 20, 2015
Chemistry for Changing Times12th Edition
Hill and Kolb
Chapter 6Gases, Liquids, Solids,
and Intermolecular Forces
John SingerJackson Community College, Jackson, MI
© 2010 Pearson Prentice Hall, Inc.
© 2010 Pearson Prentice Hall, Inc.
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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.
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Intermolecular Forces and the States of Matter
Melting 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.
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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.
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Intermolecular Forces and the States of Matter
Dipole forces: Polar molecules exist as dipoles. These oppositely charged ends will attract each other.
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Intermolecular Forces and the States of Matter
Hydrogen 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 Matter
Dispersion 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 Matter
Solution: 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.
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Intermolecular Forces and the States of Matter
Ionic substances dissolve in water through ion-dipole interactions.
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The Gas LawsKinetic Molecular Theory of a Gas
Postulates: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
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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
Standard temperature and pressure:
Standard temperature = 0 oC
Standard pressure = 1 atm
A mole of any gas at STP occupies 22.4 L
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The Gas Laws
Combined gas law:
P1V1 = P2V2
T1 T2
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The Gas Laws
Ideal gas law:
PV = nRT
R = 0.0821
Kmol
atmL