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Instructions to students and safety in the laboratory.

  Students should work only on their designated seats during practical classes. While working in the laboratory, each student should be in an apron with a nameplate. Never work alone in a practical laboratory. The student must be careful while working in the laboratory with chemicals, glassware or samples to be tested as they are potentially dangerous if wrongly handled. Before coming to practical classes, every student shall bring his/her own permanent glass marker pen, notebook, hand-gloves, and practical manual. All glassware to be used should be rinsed with distilled water before performing the practical exercise. Do not displace the reagent bottles and instruments from their assigned places. If the large bottles and beakers, containing solutions/reagents, are heavy in weight, never carry the bottles by holding the neck and the glass-beakers with the help of fingers. Hold them within the grip of both hands, while carrying them from one place to another. Keep your...

Molisch's Test- Definition, Principle, Procedure, Result, Uses

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Molisch Test Definition  Molisch's Test is a general test for all carbohydrates.      Objectives of Molisch Test To identify the presence of carbohydrates in a given sample. To differentiate   carbohydrates from other biomolecules. Principle of Molisch Test Diagrammatically representation of the principle of Molisch's Test Image Source:   AlexNB , Public domain, via Wikimedia Commons Concentrated sulphuric acid dehydrates carbohydrates to give furfural (in the case of pentoses) and furfural derivatives (in the case of hexoses and heptoses). These furfural derivatives condense with alpha naphthol to form a violet-coloured compound.  Oligosaccharides and polysaccharides are first hydrolysed to monosaccharides by concentrated acid. They undergo dehydration to form furfural or its derivatives. Requirements Reagents:  Molisch’s Reagent: Dissolve 1 gm  α -naphthol in 95% ethyl alcohol and make the volume 100 ml. Concentrated H 2 SO 4...