Chemistry Project2017- 2018 Preparation of Potash Alum From Scrap Aluminium Submitted by: Soumyadeep Basu Class 12 (Science) Roll no.- : Signature of Internal Signature of External Examiner Examiner __________________ __________________ . Date: Registration No. Sudhir Memorial Institute.Preparation of Potash Alum Name of Institute: Sudhir Memorial Institute. Liluah has satisfactorily completed the project in Chemistry for the CBSE in the year 2017-2018. Liluah LABORATORY CERTIFICATE This is to certify that Soumyadeep Basu of class Twelve. Preparation of Potash Alum Acknowledgement I would like to thank our school chemistry teacher their guidance and support. Finally I would like to thank CBSE for giving me this opportunity to undertake this project. I would also like to thank my parents and my sister for encouraging me during this course of this project. . I also thank the school principal for giving me the opportunity for doing such a project. The recycling of aluminium cans and other aluminium products is a very positive contribution to saving our natural resources. M = Trivalent cation such as Fe 3+. K+. AL3+.24H2O Where.M2 (SO4)3. Being good conductor of electricity it is used for transmission of electricity. high tensile strength and resistance and resistance to corrosion is widely used for the manufacture of aeroplanes. NH4+ etc. Cr 3+ etc. automobiles lawn furniture as well as for aluminium cans. Aluminium is also used for making utensils.Preparation of Potash Alum Introduction Aluminium because of its low density. Alums are double sulphates having general formula X2SO4. X = Monovalent cation such as Na+. the most common of which are the alums. Most of the recycled aluminium is melted and recast into other aluminium metal products or used in the production of various aluminium compounds. . Chrome Alum (NH)2SO4.24H2O .Ferric Alum Potash alum is used in papermaking. .Cr2 (SO4)3. Soda Alum K2SO4.Al2 (SO4)3.24H2O .24H2O .Fe2(SO4)3. in fire extinguishers in food stuffs and in purification of water soda alum used in baking powders and chrome alum is used in tanning leather and water proofing fabrics.Preparation of Potash Alum Some important alum and their names are given below: K2SO4.Potash Alum Na2SO4.Al2 (SO4)3.24H2O . Preparation of Potash Alum . Preparation of Potash Alum Aim To prepare potash alum from aluminium scrap . Preparation of Potash alum Requirements 250 ml conical flask Funnel Beaker Scrap aluminium or cola can Potassium hydroxide solution (KOH) 6 M Sulphuric Acid (H2SO4) Water Bath Ethanol . Sulphuric acid first gives precipitate Al(OH)3. salt. 2KOH(aq) + H2SO4(aq) 2Al(OH)3 (s) + K2SO4(aq) + 2H2O(l) 2Al(OH)3 (s) + 3 H2SO4(aq) Al2(SO4)3(aq) +6H2O(l) The resulting solution is concentrated to near saturation and cooled. On cooling crystals of potash alum crystallize out. 2Al(s) + 2KOH (aq) + 6H2O (l) 2KAl(OH)4 (aq) + 3H2 Potassium aluminate solution on treatment with dil. 24H2O(s) .Preparation of Potash alum Theory Aluminum metal is treated with hot aqueous KOH solution. Aluminium dissolves as potassium aluminate. K2SO4(aq) + Al2(SO4)3(aq) + 24H2O(l) K2SO4. KAl(OH) 4. which dissolves on addition of small excess of H2SO4 and heating.Al2(SO4)3. 24H2O(s) .Preparation of Potash alum Reactions 2Al(s) + 2KOH(aq) + 6H2O(l) 2KAl(OH)4 (aq) + 3H2 K2SO4(aq) + Al2(SO4)3(aq) + 24H2O(l) K2SO4.Al2(SO4)3. 24H2O(s) 2Al(OH)3 (s) + 3 H2SO4(aq) Al2(SO4)3(aq) +6H2O(l) 2KOH(aq) + H2SO4(aq) 2Al(OH)3 (s) + K2SO4(aq) + 2H2O(l) K2SO4(aq) + Al2(SO4)3(aq) + 24H2O(l) K2SO4.Al2(SO4)3. Put the small pieces of scrap aluminium or aluminium foil (about 1.00g) into a conical flask and add about 50 ml of 4 M KOH solution to dissolve the aluminium. Continue heating until all of the aluminium reacts. Aluminium foil may be taken instead of scrap aluminium. Since during this step hydrogen gas is evolved this step must be done in a well ventilated area. The flask may be heated gently in order to facilitate dissolution. Filter the solution to remove any insoluble impurities and reduce the volume to about 25 ml by heating. .Preparation of potash Alum Procedure Clean a small piece of scrap aluminium with steel wool and cut it into very small pieces. Preparation of Potash alum Allow the filtrate to cool. In case crystals do not form the solution may be further concentrated and cooled again. Cool the resulting solution in an ice-bath for about 30 minutes whereby alum crystals should separate out. . Gently heat the mixture until the Al(OH)3 precipitate dissolves. For better results the solution may be left overnight for crystallization to continue. wash the crystals with 50/50 ethanol-water mixture. Continue applying the vacuum until the crystals appear dry. Now add slowly 6 M H2SO4 until insoluble Al(OH)3 just forms in the solution. Filter the crystals from the solution using vacuum pump. Determine the mass of alum crystals. Preparation of Potash Alum Observations Mass of aluminium metal =…………….g Theoretical yield of potash alum =……………g Percent yield =……………% .g Mass of potash alum =……………. Preparation of Potash Alum Result Potash alum was prepared from aluminium scrap. . com books.com Wikipedia .co. Bibliography http://www.cbseportal.in Chemicalland.google.