Chapter 2 Colligative Properties of Dilute Solution
Chapter 2 Colligative Properties of Dilute Solution
Solubility Vapor pressure and Vapor pressure lowering of solution Boiling-point elevation and freezing-point depression O mosiS
Solubility Boiling-point elevation and freezing-point depression Vapor pressure and Vapor pressure lowering of solution Osmosis
2.1 Solubility Nacl(s)+ HO Na(aq)+ Cl(aq) Solubility The solubility is defined as the amount that dissolves in a given quantity of water at a given temperature to give a saturatea solution
2.1 Solubility NaCl (s) + H2O Na+ (aq) + Cl- (aq) Solubility: The solubility is defined as the amount that dissolves in a given quantity of water at a given temperature to give a saturated solution
2.1.1 Saturated solution State A solution is in dynamic equilibrium with respect dissolved substance A dynamic equilibrium is reached in which the rate at which ions leave the crystals equals the rate at which ions return to the crystals
2.1.1 Saturated solution State: A solution is in dynamic equilibrium with respect dissolved substance. A dynamic equilibrium is reached in which the rate at which ions leave the crystals equals the rate at which ions return to the crystals
2.1.2 Unsaturated solution A solution not in equilibrium with respect to a given dissolved substance and in which more of the substance can dissolve 2.1.3 Supersaturated solution A solution that contains more dissolved substance than a saturated solution does
2.1.2 Unsaturated solution A solution not in equilibrium with respect to a given dissolved substance and in which more of the substance can dissolve. 2.1.3 Supersaturated solution A solution that contains more dissolved substance than a saturated solution does
2.2 Vapor Pressure Lowering of A Solution 2.2.1 Vapor-pressure evaporation HOO condensation H2O(g) 1: liquid phase g: gas phase Definition When a dynamic equilibrium is reached in the liquid and gas phase at a given temperature, the saturated vapor pressure of this system is the vapor-pressure (symbol p). The unit is Pa or kPa
2.2 Vapor Pressure Lowering of A Solution 2.2.1 Vapor-pressure H2O (l) H2O (g) evaporation condensation l: liquid phase g: gas phase Definition: When a dynamic equilibrium is reached in the liquid and gas phase at a given temperature, the saturated vapor pressure of this system is the vapor-pressure (symbol p ). The unit is Pa or kPa
IPA Surface G as phase of water Liquid phase
Gas phase Liquid phase Surface of water pA 0
P/kPa 101.3 Ether Ethanol Water Polyglycol 34.6 78.5 100T/C The vapor pressure of Some liquid
34.6 78.5 100 101.3 P/kPa T/℃ The vapor pressure of Some liquid Polyglycol Ether Ethanol Water
Essential %I. p: Its unit is Pa or kPa 62. p related to the quality of solvent. Every kinds of liquid have different vapor-pressure 483. p related to the temperature of solvent. When the temperature is elevated, the p value will Increase 94. If the p value of a substance is larger, we'll call it volatile. And less. nonvolatile 45. The p value of solid substance is very little. But it has the ability of sublimation
Essential ❖1. p : Its unit is Pa or kPa. ❖2. p related to the quality of solvent. Every kinds of liquid have different vapor-pressure. ❖3. p related to the temperature of solvent. When the temperature is elevated, the p value will increase. ❖4. If the p value of a substance is larger, we’ll call it volatile. And less, nonvolatile. ❖5. The p value of solid substance is very little. But it has the ability of sublimation
2.2.2 Vapor-pressure lowering If the solute is nonvolatile p. is the total vapor pressure of the solution. Because the mole fraction of solvent in a solution is always less than that for the pure solvent; the vapor pressure is lowered
2.2.2 Vapor-pressure lowering If the solute is nonvolatile, pA is the total vapor pressure of the solution. Because the mole fraction of solvent in a solution is always less than that for the pure solvent; the vapor pressure is lowered
