PREPARATION OF STANDARD VITAMIN C CURVE

Place 100mg ascorbic acid in 100ml standard flask and make it up to the mark[1mg/ml],prepare the standard curve of the vitamin c by adding the required weight of the ascorbic acid to the extracting solvent to make 100ml..
Dilute 1ml of the standard mixture to 10ml with 4% TCA[trichloroacetic acid] solution..add 0.75g acid washed norit and shake vigorously and filter...place 2ml of each filtrate in two test tubes,add 1 drop of 10% thiourea solution and 0.5ml of 2.4--DNP[dinitrophenylbenzene] reagent.....place the two test tubes in a water bath at 37degree celcius for 3hours and then place it in a beaker of ice water ..then add 25ml of 98% tetraoxosulphate acid[H2SO4] in dops form the burette in 1 min...then take the absorbance after 30 minutes using jenway 6051 calorimeter..then plot the graph of absorbance against concentration to obtain standard ascorbic acid curve...

SAMPLE PREPARATION
Extract 2.0g of milled sample with 25ml of 0.1% oxalic acid,centrifuge the mixture and transfer the supernatant into a 50ml standard flask..wash the residue 2 times with 10ml of 1.0 oxalic acid,pool it together and make it up to 50ml mark with the extracting solvent..then follow the above outlined procedure and make triplicate analysis....

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SYNTHESIS OF DYE AND TIE-DYEING

APPARATUS--->

Round-bottomed flask, Condenser, Measuring cylinder, conical flask, Glass rod stirrer suction pump, suction funnel, filter paper, capillary tube....

REAGENT--->

1-chloro-2, 4-dinitrobenzenaniline, ethanol, sodium acetate.....

PROCEDURE---->

 3g of 1-Chloro-2, 4-dinitrobenzene was dissolved in a 10cm3 round-bottom flask with 1.5g Aniline, and 25cm3 Ethanol. 7.5g of Sodium Acetate was measured and added to the solution and stirred. The mixture was then heated under reflux for 30 minutes. While still hot, it was filtered hot; the precipitate (a spike-like structure) which is the product was allowed to dry......

YIELD
A small sample

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SYNTHESIS OF HEXAAMINECOBALT[III]CHLORIDE

On an analytical balance,measure 2grams of cobalt[ii]chloride and 0.4grams of ammonium chloride,pour the two into a beaker and add 5ml of water...,add 1.0g of activated charcoal into the solution,then add 5ml of concentrated aqueous ammonia....into a 10ml graduated cylinder,draw 5ml of 10% hydrigen peroxide solution...add it  very slowly into the solution and stir constantly..when the bubbling has stopped,gently heat the cobalt solution in the hood for 5minutes with a small bunsen flame..Allow the solution to stand for half hour..Remove the activated charcoal by passing the solution through filter paper on buchner funnel using suction..pour the filtrate into a 150ml beaker and 20ml of concentrated HCL..Stir the solution thoroughly and isolate the orange precipitate of hexaaminecobalt[iii]chloride by filtration through the buncher funnel with suction..Continue to draw air through the funnel for several minutes to help dry the solid product..Finish drying the product by pressing the crystals between two pieces of paper..then weigh....

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HOW TO SYNTHESIS AQUOPENTAAMINECOBALT[III]CHLORIDE

Obtain a 5ml sample cobalt[ii]chloride solution..the sample must contain 1g of cocl2...place the cobalt solution into a 150ml beaker and add 0.2g of ammonium chloride and 11ml of concentrated ammonia solution...draw 5ml of 10% hydrogen peroxide solution into a 10ml graduated cylinder....slowly add the hydrogen peroxide solution to the cobalt[ii]chloride solution and stir constantly...when the bubbling has stopped,place the beaker containing the dark red cobalt solution under the hood and gently aerate for 1 hour...after the compressed air has been stopped,add 15ml of concentrated  HCL to the cobalt solution..if a red precipitate does not form in a few minutes,add 15ml more of the HCL solution,isolate red precipitate of AQUOPENTAAMINECOBALT[III]CHLORIDE by filtration through buchner funnel,using suction..continue to draw air through the precipitate by suction for several minutes,after the solvent has been removed to partially dry the solid...press the solid dry between pieces of filter paper and weigh the dried crystals..

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PREPARATION OF TETRAAMINECOPPER[II]SULPHATE MONOHYDRATE CRYSTALS

Weigh out 7.0g of CUSO4.5H20 on a triple-beam or other rough balance.weigh the solid either on a clean piece of paper without coloured strips or a small beaker and not directly on the balance pan.Transfer the solid copper sulphate to a 125ml erlenmeyer flask and add 15ml of water.heat the flask to dissolve the solid,then cool to room temperature.carry out the remaining steps under the hood..add concentrated ammonia solution,a few ml at a time shaking the flask constantly untill the first precipitate has completely dissolved.All the copper should now be present in the solution as complex ion ''TETRAAMINECOPPER[II]...The sulphate salt of this complex cation can be precipitated by the addition of a liquid such as methanol in which the ''TETRAAMINECOPPER[II]SULPHATE MONOHYDRATE is insoluble..Add 10ml of methanol to the solution,this should result in the formation of deep blue precipitate of the above complex.Filter the solution through a buchner funnel by suction drying..Dry the solid by pressing it between two pieces of filter paper..Transfer the dried crystals to a weighed test tube and re-weigh..then determine the percentage yield...percentage yield= actual yield/theoretical yield * 100%.....

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