Factors Affecting Solubility and Colligative Properties
Solubility refers to the maximum amount of solute that dissolves in a given amount of solvent at a particular temperature
Factors Affecting Solubility
1. Effect of Temperature
For some substances to dissolve in a given solvent, heat is absorbed. The reaction is endothermic. In this case, an increase in temperature increases solubility. For some substances, heat is released when they dissolve in a given solvent. The reaction is called exothermic. In this case, an increase in temperature decreases solubility.
Generally, an increase in temperature decreases solubility. Solids in liquid solution increases solubility. But for solubility of gas in liquids, an increase in temperature decreased solubility because gas evaporates as temperature increases.
2. Effect of Pressure
Pressure unlike temperature has little effect on solutions unless the solute is a gas. An increase in pressure causes greater interaction between particles of the gas and the liquid, thus, increasing solubility.
3. Nature of the Solute and Solvent Nature of both solute and the solvent affect the solubility. Substances with similar intermolecular attractive forces tend to be soluble in one another. This generalization is stated as “like dissolves like”. Non polar solutes are soluble in non polar solvents; polar or ionic solutes are soluble in polar solvents. Liquids that are attracted by charged objects are composed of polar molecules, those that are not attracted by a charged body are non polar.
COLLIGATIVE PROPERTIES properties of solutions that depend upon the ratio of the number of solute particles to the number of solvent molecules in a solution.
Colligative properties include: 1. Relative lowering of vapor pressure 2. Elevation of boiling point 3. Depression of freezing point 4. Osmotic pressure
Vapor Pressure
The vapor pressure of a liquid is the pressure of a vapor in equilibrium with the liquid phase. The
Factors Affecting Solubility
1. Effect of Temperature
For some substances to dissolve in a given solvent, heat is absorbed. The reaction is endothermic. In this case, an increase in temperature increases solubility. For some substances, heat is released when they dissolve in a given solvent. The reaction is called exothermic. In this case, an increase in temperature decreases solubility.
Generally, an increase in temperature decreases solubility. Solids in liquid solution increases solubility. But for solubility of gas in liquids, an increase in temperature decreased solubility because gas evaporates as temperature increases.
2. Effect of Pressure
Pressure unlike temperature has little effect on solutions unless the solute is a gas. An increase in pressure causes greater interaction between particles of the gas and the liquid, thus, increasing solubility.
3. Nature of the Solute and Solvent Nature of both solute and the solvent affect the solubility. Substances with similar intermolecular attractive forces tend to be soluble in one another. This generalization is stated as “like dissolves like”. Non polar solutes are soluble in non polar solvents; polar or ionic solutes are soluble in polar solvents. Liquids that are attracted by charged objects are composed of polar molecules, those that are not attracted by a charged body are non polar.
COLLIGATIVE PROPERTIES properties of solutions that depend upon the ratio of the number of solute particles to the number of solvent molecules in a solution.
Colligative properties include: 1. Relative lowering of vapor pressure 2. Elevation of boiling point 3. Depression of freezing point 4. Osmotic pressure
Vapor Pressure
The vapor pressure of a liquid is the pressure of a vapor in equilibrium with the liquid phase. The