* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Chapter 13 Notes Types of Solutions Saturated Solution: contains
Survey
Document related concepts
Supercritical fluid wikipedia , lookup
Liquid crystal wikipedia , lookup
Chemical equilibrium wikipedia , lookup
Acid–base reaction wikipedia , lookup
Acid dissociation constant wikipedia , lookup
History of electrochemistry wikipedia , lookup
Marcus theory wikipedia , lookup
Franck–Condon principle wikipedia , lookup
Physical organic chemistry wikipedia , lookup
Degenerate matter wikipedia , lookup
Stability constants of complexes wikipedia , lookup
Ultraviolet–visible spectroscopy wikipedia , lookup
Nanofluidic circuitry wikipedia , lookup
State of matter wikipedia , lookup
Equilibrium chemistry wikipedia , lookup
Transcript
Chapter 13 Notes Types of Solutions Saturated Solution: contains the maximum amount of a solute that will dissolve in a given solvent at a specific temperature. Unsaturated Solution: contains less solute than it has the capacity to dissolve. Supersaturated Solution: contains more solute than is present in a saturated solution (very unstable). Crystallization: the process in which dissolved solute comes out of a solution and forms crystals. A Molecular View of the Solution Process *The ease with which a solute particle replaces a solvent molecule depends on the relative strengths of three types of interactions: 1) solvent-solvent interaction 2) solute-solute interaction 3) solvent-solute interaction 3 steps are involved in the solution process: 1) separation of solvent molecules 2) separation of solute molecules 3) solvent and solute molecules mix Solute-solvent attraction > solvent-solvent attraction and solute-solute attraction; exothermic reaction Solvent-solvent and/or solute-solute attraction > solute-solvent attraction; endothermic reaction Increase in disorder of the system favors the solubility of a substance, even in an endothermic reaction Solubility is a measure of how much solute will dissolve in a solvent at a specific temperature (like dissolves like) Miscible: Liquids that are completely soluble in each other in all proportions. (Alcohols in water) Salvation: the process in which an ion or a molecule is surrounded by solvent molecules arranged in a specific manner. (When the solvent is water, this process is called hydration) (Solubility Rules pg. 123) Concentration Units Concentration: the amount of solute present in a given amount of solution. Percent by Mass: (Percent by weight or weight percent) the ratio of the mass of a solute to the mass of the solution, multiplied by 100 percent. Mole Fraction (X): Molarity (M): Molality (m): Density: The Effect of Temperature on Solubility *In most cases, the solubility of a solid substance increases with temperature Fractional Crystallization: the separation of a mixture of substances into pure components on the basis of their differing solubility (Works well if the substances involved have greatly differing solubility curves and the contamination/impurity amount is small). *Generally, gases solubility in water decreases with increasing temperature The Effect of Pressure on the Solubility of Gases Henry’s Law: the solubility of a gas in a liquid is proportional to the pressure of the gas over the solution. Where Sg = solubility of the gas in solution phase, Pg = partial pressure of the gas over the solution, k = Henry’s law constant Colligative Properties of Nonelectrolyte Solutions Colligative Properties: properties that depend only on the number of solute particles in solution and not on the nature of the solute particles. (vapor-pressure lowering, boiling point elevation, freezing-point depression, osmotic pressure). Nonvolatile: substance does not have measurable vapor pressure. Volatile: substance that has measurable vapor pressure. Raoult’s Law: the partial pressure of a solvent over a solution = (vapor pressure of the pure solvent) * (the mole fraction of the solvent in the solution) Ideal Solution: Any solution that obeys Raoult’s Law (Benzene in Toluene) (Heat of Solution = 0) Non-ideal Solutions have 2 cases: 1) Intermolecular forces between A and B molecules are weaker than those forces between A molecules and B molecules; positive deviation, endothermic reaction. 2) A molecules attract B molecules more strongly than they do their own kind; negative deviation, exothermic reaction. Boiling-Point Elevation: (the boiling point of the solution) – (the boiling point of the pure solvent). (Concentration is in molality because of changing temperature). Freezing-Point Depression: (the freezing point of the pure solvent) – (the freezing point of the solution). (Concentration is in molality because of changing temperature). Osmosis: the selective passage of solvent molecules through a porous membrane from a dilute solution to a more concentrated one. Semi-permeable membrane: allows the passage of solvent molecules but blocks the passage of solute molecules. Osmotic Pressure: the pressure required to stop osmosis. ( Isotonic Solution: Two solutions that have equal concentration and the same osmotic pressure. Hypertonic Solution: The solution of greater concentration in a solution of unequal osmotic pressure. Hypotonic Solution: The solution of lesser concentration in a solution of unequal osmotic pressure. Colligative Properties of Electrolyte Solutions Van’t Hoff factor: (i=1 for all nonelectrolytes) *Osmotic pressure = iMRT Ion pair: one or more cations and one or more anions held together by electrostatic forces Colloids Colloid: a dispersion of particles of one substance (the dispersed plane) throughout a dispersing medium made of another substance. Aerosol: consists of liquid droplets or solid particles dispersed in a gas (Smoke, Fog) Emulsion: consists of a liquid droplets dispersed in another liquid (Mayonnaise) Sol: a suspension of solid particles in a liquid (Milk of magnesia) Tyndall effect: When a beam of light passes through a colloid, it is scattered by the dispersed phase. This is why the Tyndall effect is used to help determine a colloid from an ordinary solution. Hydrophilic: water-loving (proteins) Hydrophobic: water-fearing (Oil on water)