• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Preparation of alum from scrap aluminium

Extracts from this document...

Introduction

Chemistry 244 Experiment 3 - The preparation of alum from scrap aluminium Dian Page 15533670 30 August 2010 Abstract The recovery of aluminium from scrap aluminium through its conversion to potash alum (KAl(SO4)2·12H2O) was investigated. It was found that a final percentage yield of 76% was obtained. In addition a final yield of 9.00g was yielded. Introduction Aluminium, because of its low density, high tensile strength and resistance and resistance to corrosion, is widely used for the manufacture of aeroplanes, automobiles, lawn furniture as well as for aluminium cans. Being a good conductor of electricity, it is used for transmission of electricity. Aluminium is also used for making utensils. The recycling of aluminium cans and other aluminium products is a very positive contribution to saving our natural resources. Most of the recycled aluminium is melted and recast into other aluminium metal products or used in the production of various aluminium compounds, the most common of which are the alums.1 Alum is a salt that is a combination of an alkali metal, such as sodium, and a trivalent metal, such as aluminium.2 & 3 Alums are double sulphates having a general formula (equation 1) ...read more.

Middle

Rinse the beaker twice with 5-mL portions of distilled water, pouring each rinse through the filter residue. Buchner filter was used. Dark black residue was left on filter paper, and the clear filtrate was obtained in the flask 7 Transfer clear filtrate to 250 ml beaker + add 10 drops of methyl indicator solution. The solution turned to a yellow colour (before acid is added) 8 Addition of 6 M H2SO4 with constant stirring. On addition of the acid, the solution got hot from a neutralization reaction occurring and a white precipitate of aluminium hydroxide formed. 18 ml of the acid (H2SO4) had to be added and the solution had to be placed on a steam bath so that Al(OH)3 will dissolve. It had a red clear colour. 9 Cool mixture in ice bath White alum crystals formed after a waiting period of 16 min and occasional stirring. 10, 11 and 12 Filter alum crystals Filter was put on longer than usual. (more effective results) White crystals stayed at the top and a pinkish/reddish filtrate was obtained in the flask below. ...read more.

Conclusion

may improve if the reaction could run longer i.e. the flasks placed longer on the steam baths, at warmer temperatures, in the fume hoods and that the filter runs longer so that the product is essentially dry. It is also noted that more H2SO4 had to be added excessively to dissolve Al(OH)3, so maybe in future experiments a super acid could be used for a more effective yield. The reason why this procedure is not used in the industry is because H2 gas burns explosively1 which means it is highly pollutant and on a large scale i.e. a big industry, the pollution will be catastrophic. KOH is also very corrosive so it can attack the machines in the factory, industry, which means it will rust and cost the company a lot of money. Sulfuric acid is also very hazardous. Conclusion The experiment illustrated an interesting example of the reduction of an environmental waste product. In doing so, reducing aluminium to potassium aluminium sulphate dodecahydrate, a final percantage yield of 76% was obtained. It was also found that a theoretical yield of 11.8g should have been yielded if all the procedures were done 100% efficiently, but because this is a practical a final yield of 9.00g was obtained. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our University Degree Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related University Degree Chemistry essays

  1. Determining the concentration of copper(II) ions

    This is very high. Looking at the result, it is only 0.10 mol dm3 lower than the actual concentration and the variation does not seem very large. However on a critical level, the error is too great to consider it accurate.

  2. Kinetics: The rates of a chemical reaction

    | / |/_________________ 0 1 2 3 4 [A] For a first order reaction, the plot is a straight line (linear), as shown above, because rate = k [A] (a straight line) Note that rate = k when [A] = 1.

  1. Synthesis of Aspirin by Green Chemistry Methods

    Table of reactions (units are all in moles) Conventional method I 0.0220 0.0529 0 0 R -0.0220 -0.0220 +0.0220 +0.0220 E 0 0.0309 0.0220 0.0220 Microwave method I 0.0101 0.0403 0 0 R -0.0101 -0.0101 +0.0101 +0.0101 E 0 0.0302 0.0101 0.0101 Acetyl salicylic acid (conventional heating method)

  2. Werner Complexes - Preparation and Determination of Structural Formula

    With this, logically dividing the charges between the cations and anions present will help determine the overall structure of the molecule. The second technique for determining the amount of ions present in a Werner complex is magnetic susceptibility. With finding the magnetic susceptibility using a magnetic susceptibility of a compound, one can calculate whether the compound is paramagnetic or diamagnetic.

  1. To study the enthalpy changes (H) of various acid-base neutralization.

    So, the heat loss in method 1 is less than method 2. Therefore, the more accurate results can be obtained. 9. Combinations of acid-alkali neutralization result from other classmates. The combination of acid- alkali neutralization Group Number Combination of acid and alkali Enthalpy change of neutralization (KJmol-1)

  2. Describe The Concept Of Oxidation Levels And Discuss The Use Of Oxidising And Reducing ...

    An indirect method of reducing alcohols to the corresponding hydrocarbon is through the intermediate tosylate by use of LiAlH4. An amino group can replace the hydroxyl group of phenols by heating the phenol with a mixture of ammonia and zinc chloride.

  1. The preparation of alum from scrap aluminium. In this experiment, instead of recycling aluminium ...

    Hydrogen gas, when burned properly, produces a large amount of heat and no pollution, the only combustion product being water (The Synthesis of Potassium Aluminium Sulfate (Alum) from Aluminium Scrap, 2005). Alum is widely used in the dyeing of fabrics, in the manufacture of pickles, in canning some foods, as

  2. Forensic Chemistry - Ion Selective Electrode. The objective of experiment is to determine ...

    of all the types of ions in solutions If background ionic strength is high and constant relative to the sensed ion concentration, the activity coefficient is constant and activity is directly proportional to concentration. Ionic strength adjustor (ISA) is added to all nitrate standards and samples so that the background

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work