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Showing posts from December, 2012

Hinsberg Test for Amine

Distinction between primary, secondary and tertiary amine Using Hinsberg  reagent Three classes of amines are distinguished by Hinsberg reagent test . The Hinsberg reagent is benzene sulphonyl chloride (C 6 H 5 SO 2 Cl). 1. Reaction of Hinsberg reagent with Primary amine A primary amine forms a precipitate of N-alkyl benzene sulphonamide with Hinsberg reagent. This precipitate is soluble in alkali. RNH 2 (primary amine)  +  C 6 H 5 SO 2 Cl ( Hinsberg reagent ) ------------>  R-NH-SO 2 -C 6 H 5   ------(NaOH)---> R-N - Na + -SO 2 C 6 H 5 (soluble) 2. Reaction of Hinsberg reagent with secondary amine   Secondary amine reacts with Hinsberg reagent to form a precipitate N,N-dialkyl benzene sulphonamide. But this precipitate is insoluble in alkali. R 2 NH (secondary amine)  +  C 6 H 5 SO 2 Cl ( Hinsberg reagent ) ------------> R 2 NSO 2 C 6 H 5 (precipitate)  -----(NaOH)---> insoluble (no reaction) 2. Reac...

General Knowledge Questions: Chemistry

GK Chemistry Questions and answer about Elements Some frequently asked Chemistry gk questions about elements Chemistry GK >> 1. Hydrogen 1. Which is the most abundant element in the Universe ? Answer: Hydrogen 2. Which is the atom without Neutron ? Answer: Hydrogen 3. Who discovered Hydrogen ? Answer: Henry Cavendish 4. Who named Hydrogen ? Answer: Lavoisier 5. Which isotope of Hydrogen has Radio Active nature ? Answer: Tritium 6. Which gas is used to make Vanaspathi ? Answer: Hydrogen 7. Which is the lightest element ? Answer: Hydrogen 8. Which is the element common to all Acid ? Answer: Hydrogen Chemistry GK >> 2. Helium  1. Which is the second most abundant element in the universe ? Answer: Helium 2. Which gas is used to for filling air ships and observation balloons ? Answer: Helium 3. Who discovered Helium ? Answer: William Ramsay 4. Which is the lightest Noble gas ? Answer:  Helium ...

Application of Adsorption

Industrial Application of Adsorption Process 1. Activated charcoal is used to remove bad odours inside refrigerator and to deodourise tap water in water purifier. It is also used in gas masks to adsorb poisonous gases in the atmosphere. 2. In sugar industry animal charcoal is used to decolourise raw sugar solution obtained from sugar cane. 3. In chromatography, suitable adsorbents are used. They selectively adsorb certain substance from solution. Adsorption chromatography is used for detection and separation of mixtures. 4. In dehumidifier, silica gel is used as adsorbent. 5. Activated charcoal is  used to maintain vacuum in laboratory vessels such as Dewar flask. 6. Heterogeneous catalysis  mostly operate through adsorption of reactant molecules. 7. Softening of water using ion exchange resin is based on selective adsorption of ions which cause hardness. 8. In mordant dyeing, mordants adsorb colour. 9. Ferric hydroxide can adsorb arsenic ions and hence i...

Adsorption Isobar

Adsorption Isobar : Effect of temperature Most of the adsorptions are exothermic reactions, Hence adsorption generally depend on temperature. Exothermic reactions are mostly spontaneous at low temperature. Hence the extent of adsorption decreases with increase of temperature at constant pressure. A plot of extent of adsorption verses temperature at constant pressure is known as adsorption Isobar.

Factors affecting adsorption

Factors affecting adsorption: Pressure of Gas Adsorption and desorption are reversible process and take place simultaneously leading to equilibrium state. Adsorbent + gas  <========> Adsorbent gas In the forward direction, during adsorption, volume decreases since gases are adsorbed to the surface. Hence applying Le-Chatelier principle, we can predict effect of pressure. At high pressure, the system has a tendency to decrease volume and shifts towards forward direction, ie , more adsorption take place. Now we can conclude that extent of adsorption (x/m) increases with increase in pressure. Where x= number of the moles of gas adsorbed and m = mass of adsorbent, at equilibrium. Variation of  x/m with pressure can be experimentally studied and can be plotted as a graph at constant temperature. Such graphs obtained by plotting (x/m) against (p) at constant temperature are called, adsorption isotherm . To see all Factors affecting adsorption of gases on...