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Chem112 Exam 1
Ch.12, 13, 14
Vocab | Definition |
---|---|
Intramolecular Forces | The forces holding atoms together to form molecules |
Intermolecular Forces | Forces between molecules, between ions, or between molecules and ions |
Ion-Ion Forces | Attraction between metal and nonmetal *Is not an intermolecular force *Salts |
Ion-Dipole Forces | The electrostatic force between an ion and a neutral molecule that has a permanent dipole moment |
Dipole-Dipole Forces | Bond between polar molecule and polar molecule *depends on atom electronegativities and molecular structure |
Hydrogen Bonding | A special form of dipole-dipole attraction, which enhances dipole-dipole attractions *Bonds with N, O, F |
Induced Dipole-Induced Dipole | Bond between nonpolar molecule and nonpolarmolecule *London dispersion *Includes noble gases and diatomic molecules |
Dipole-Induced Dipole Forces | Dipole moment of polar molecule and polarizability of nonpolar molecule |
Polarization | The process of inducing a dipole |
Polarizability | The extent to which the electron cloud of an atom or molecule can be distorted by an external electric charge |
Vapor Pressure | The pressure of the vapor of a substance in contact with its liquid or solid phase in a sealed container |
Normal Boiling Point | The temperature at which the change from a liquid to gas occurs *T(C)=100 P(mmHg)=760 |
Heat of Vaporization | The heat required (at constant P) to vaporize the liquid |
Phase Diagram | A graph showing which phases of a substance exist at various temperatures and pressures |
Triple Point | All three phases are in equilibrium *T(C)=0.0098 P(mmHg)=4.58 |
Freezing Point | The temperature at which the change from a liquid to solid occurs *T(C)=0 P(mmHg)=760 |
Critical Point | Combination of critical temperature and critical pressure. The liquid and gas phases have exactly the same density |
Critical Pressure | Minimum pressure needed to liquefy a substance at the critical temperature |
Critical Temperature | Temperature above which the gas can no longer be liquefied, regardless of pressure. The highest temperature at which a substance can exist as a liquid |
Sublimation | Solid to a gas |
Le Chatelier's Principle | The behavior of water under pressure. A change in any of the factors determining an equilibrium will cause the system to adjust to reduce the effect of the change |
Melting | Solid to a liquid |
Freezing | Liquid to a solid |
Vaporization | Liquid to a gas |
Condensation | Gas to a liquid |
Deposition | Gas to a solid |
Heating Curve | A plot of temperature versus time where heat is added |
Cooling Curve | A plot of temperature versus time when heat is removed |
Solution | A homogenous mixture in a single phase |
Evaporation | Liquid to a gas |
Henry's Law | The concentration of a gas dissolved in a liquid at a given temperature is directly proportional to the partial pressure of the gas above the liquid |
Solid | The phase of matter in which a substance has both definite shape and definite volume |
Liquid | The phase of matter in which a substance has no definite shape but no definite volume |
Gas | The phase of matter in which a substance has no definite shape and a volume defined only by the size of its container |
Super Critical Fluid | A substance at or above the critical temperature and pressure |
Molarity (M) | moles of solute/liter of solution |
Molality (m) | moles of solute/kilogram solvent |
Mole Fraction (X) | moles of solute/total moles present |
Mass Precentage (%) | mass of solute x 100% |
Parts per million (ppm) | mass of solute/mass of solution x 10^6 |
Parts per billion (ppb) | mass of solute/mass of solution x 10^9 |
Raoult's Law | The vapor pressure of the solvent is proportional to the mole fraction of the solvent in a solution |
Ideal Solutions | Solutions that obey Raoult's law, in which the intermolecular forces in the two pure liquids are almost identical in both kind and magnitude and the change in enthalpy on solution formation is essentially zero |
Real Solutions | Exhibit positive or negative deviations from Raoult's Law because the intermolecular interactions between the two components A and B differ |
Negative Deviation | They like each other so much that they wait (analogy of waiting to get a ticket) |
Positive Deviation | They dislike each other so much that they hurry (analogy of waiting to get a ticket) |
Simple Distillation | A single distilling column. They give reasonable separations |
Fractional Distillation | Gives increased separation because of the increased surface area |
Colligative Properties | The properties of a solution that depend only on the number of solute particles per solvent molecule and not on the nature of the solute or solvent *Boiling Point Elevation*Freezing Point Depression*Vapor Pressure*Osmotic Pressure |
van't Hoff factor | Apparent number of particles in solution divided by the number moles of solute dissolved |
Osmotic Pressure | The difference in pressure between the two sides of the membrane |
Osmosis | The net flow of solvent through a membrane due to different solute concentrations |
Amalgams | Usually solids, are solutions of metals in liquid mercury |
Colloid | A state of matter intermediate between a solution and a suspension, in which solute particles are large enough to scatter light but too small to settle out |
Gel | A colloid dispersion with a structure that prevents it from flowing |
Sol | A colloidal dispersion of a solid substance in a fluid medium |
Aerosol | A dispersion of solid and liquid particles in a gas |
Emulsion | A dispersion of one liquid phase in another liquid with which it is immiscible |
Micelle | Liquids of detergents in water form organized spherical or cylindrical aggregates, which minimize contact between the hydrophobic tails and water |
Phospholipids | A large class of biological molecules that consist of detergent-like molecules that contain a hydrophilic head and two hydrophobic tails |