Colligative solutions Essay Example

Colligative solutions Paper A 10% salt solution was said to lower the melting point to -FCC (OFF) and a 20% salt solution was said o lower it to -ICC (205). A more formal treatment Of freezing point depression is given by Ebbing. The freezing point depression Taft is a colligating property of the solution, and for dilute solutions is found to be proportional to the molar concentration CM of the solution: ;TFH = CFML Where Kef is called the freezing-point. Depression constant. A pleasant application of the freezing point depression is in the making of homemade ice cream. The ice cream mix is put into a metal container which is surrounded by crushed ice. Then salt is put on the ice to lower its melting point, The melting of the solution tends to lower the equilibrium temperature of the ice/water solution to the melting point of the solution. This gives a temperature gradient across the metal container into the saltwater-ice solution which is lower than COO. The heat transfer out of the ice cream mix allows it to freeze. Boiling Point Elevation in Solutions The boiling point of pure water is COO, but that boiling point can be elevated by the adding of a solute such as a salt. A solution typically has a measurably higher boiling point than the pure solvent. A treatment of boiling point elevation is given by Ebbing. The boiling point elevation Debt is a colligating property of concentration CM of the solution: Debt = Kbps Where KGB is called the boiling-point-elevation constant. We will write a custom essay sample on Colligative solutions specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Colligative solutions specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Colligative solutions specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Solutions may be produced for the purpose of raising the boiling point and lowering the freezing point, as in the use Of ethylene glycol in automobile cooling systems. The ethylene glycol (antifreeze) protects against freezing by lowering the freezing point and preprints a higher operating temperature by raising the boiling point. Vapor pressure lowering[till The vapor pressure of a liquid is the pressure off vapor in equilibrium with the liquid phase, The vapor pressure of a solvent is lowered by addition of a non- volatile solute to form a solution. For an ideal solution, the equilibrium vapor pressure is given by Rallys law as , where is the vapor pressure tooth pure component A, a, and is the mole fraction of the component i in the solution For a solution with a solvent (A) and one non-volatile solute and The vapor pressure lowering relative to pure solvent is , which is proportional to the mole fraction of solute. If the solute dissociates in solution, then the vapor pressure lowering is increased by the van Hoff factor , which represents the true number of solute particles for each formula unit. For example, the strong electrolyte Magic dissociates into one Might ion and tuft CLC-ions, so that if unionization is complete, 3 and _ The measured colligating properties show that i is somewhat less than 3 due to ion association. Osmotic pressure[edit] For more details on this topic, see Osmotic pressure. The osmotic pressure Of a solution is the difference in pressure between the elution and the pure liquid solvent when the two are in equilibrium across a comparable membrane, Which allows the passage Of solvent molecules but not of solute particles. Fifth two phases are at the same initial pressure, there is a net transfer of solvent across the membrane into the solution known as osmosis. The process stops and equilibrium is attained when the pressure difference equals the osmotic pressure. Two laws governing the osmotic pressure of a dilute solution were discovered by the German botanist W. F. P. Prefer and the Dutch chemist J. H. Vans Hoff: 1. The osmotic pressure of a dilute solution at constant temperature is directly proportional to its concentration. 2. The osmotic pressure to a solution is directly proportional to its absolute temperature. These are analogous to Boles law and Charlies Law for gases. Similarly, the combined ideal gas law, , has as analog tort ideal solutions , where is osmotic_ pressure; V is the volume; n is the number of moles of solute; R is the molar gas constant 8. 314] K-1 mol-l; T is absolute temperature; and i is the Van t Hoff factor. The osmotic pressure is then proportional to the molar concentration , nice The osmotic pressure is proportional to the concentration of solute particles CIA and is therefore a colligating property. As with the Other colligating properties, this equation is a consequence of the equality of solvent chemical potentials of the two phases in equilibrium. In this case the phases are the pure solvent at pressure P and the solution at total pressure P -e n. (5] Pioneers of Sociology * Karl Marx He said that the working class Will defeat the ownership class, and result in a utopia where government will wither away to nothing and the Renville of economics will be based on For each according to his needs, and from each according to his ability. His contribution to thinking in sociology is mainly in a perspective called Conflict Theory in which social organization and change is based upon conflicts built into society, Many people see this as having much resemblance to classical (Greek and Latin) myths about the Phoenix Bird (who flies too close to the sun and burns) and creation myths of Toothpaste people of the Great Plains of North America. It is ironical that he predicted revolution to take place in industrialized societies, but the only unionism revolutions in history took place in large agrarian feudal societies (as Russia and China were), Dialectical materialism and conflict approach, * Augusta Comet He was the founder of French positivism. Comet can also be given credit for inventing or coining the term sociology, Comets philosophy of positivism developed from historical studies of the human mind. This led to Comets views of the three stages of the history of sciences. In order as follows, the stages are: 1) Theological nature has a will of its own.