The Effect of the Molecular Weight to the Rate of Diffusion

Only available on StudyMode
  • Download(s) : 1211
  • Published : September 17, 2010
Open Document
Text Preview
The effect of the molecular weight to the rate of diffusion
Based on the experiments, sd f f f f s wrefwe fwe rfwjv rwefhnw fwer fwe fwef fwe fwe fwe fwef wef w fwe fwe From Wikipedia, the free encyclopedia Jump to: navigation, search
Sucrose is the organic compound commonly known as table sugar and sometimes called saccharose. This white, odorless, crystalline powder has a pleasing, sweet taste. It is best known for its role in human nutrition. The molecule is a disaccharide derived from glucose and fructose with the molecular formula C12H22O11. About 150,000,000 tonnes are produced annually.[2] Structural β-D-fructofuranosyl-(2→1)-α-D-glucopyranoside In sucrose, the component glucose and fructose are linked via an ether bond between C1 on the glucosyl subunit and C2 on the fructosyl unit. The bond is called a glycosidic linkage. Glucose exists predominantly as two isomeric "pyranoses" (α and β), but only one of these forms the links to the fructose. Fructose itself also exists as a mixture of forms, each of which has α and β isomers, but again only one particular isomer links to the glucosyl unit. What is notable about sucrose is that unlike most disaccharides, the glycosidic bond is formed between the reducing ends of both glucose and fructose, and not between the reducing end of one and the nonreducing end of the other. This linkage inhibits further bonding to other saccharide units. Since it contains no anomeric hydroxyl groups, it is classified as a nonreducing sugar. Crystallography is the technique that gives highly precise information on molecular structure. Sucrose crystallizes in the monoclinic space group P21, with values at 300 K being a = 1.08631 nm, b = 0.87044 nm, c = 0.77624 nm, β = 102.938°.[3][4] The usual measure of purity of sucrose is by polarimetry — the measurement of the rotation of plane-polarized light by a solution of sugar. The specific rotation at 20 °C using yellow "sodium-D" light (589 nm) is +66.47°. Commercial samples of sugar...
tracking img