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

Synthesis of Aspirin

Extracts from this document...


The aim of this practical is to carry out a chemical reaction between salicylic acid with anhydride. This will allow us to calculate the percentage yield. The chemical company for which you work has developed a new laboratory method for synthesising aspirin which produces a high yield of pure product. Before investing the large amount of money it would take to scale up the process for mass production of aspirin, the directors want to know if this new method is significantly better than existing methods, in terms of the percentage yield and purity of aspirin produced. Theory Aspirin, which is sometimes called acetylsalicylic acid, was first made in 1893 by a German chemist Felix Hofmann. Aspirin is classified as organic ester and organic acid. It is mostly used in medicine like pain killers and also they are used for reducing fever. ...read more.


The salicylic acid is like a white powder. * Once I measured the salicylic acid and the weighing boat after this I had to add it to 6ml of acetic anhydride once I add this no reaction took place but there was a colour change which changed from see through. * Before the acetic anhydride was added and now it has turned cloudy once the acetic anhydride was added. The only observation I can pick out from acetic anhydride was the smell, it smelt like vinegar it might mean that this could be used in the process of alcohol. * After the two has turned cloudy you will place them in a hot water bath then once in the hot water it will become see through and also the vinegar smell gets stronger. * I started to add drops of water into the beaker nothing happened but when I added 20ml of cold water it had a quick reaction when I added it had a white emulsion for couple of seconds and then went away. ...read more.


Moles of 2-hydroxybenzoic 3 = 0.0217mol 138 4) Assuming that all of the 2-hydroxybenzoic acid is converted into aspirin, deduce the number of moles of aspirin produced in theory (Theoretical yield) Salicylic acid (138 g/mol): limiting reactant: Acetic Anhydride 0.003kg = 3g 3g / (138 g/mol) = 0.0217 moles molar mass of aspirin x acetic anhydride moles = Theoretical yield 180.157 x 0.0247 = 4.45g Acetic Anhydride (102 g/mol): 6ml= 2.52g 2.52g / (102 g/mol) = 0.0247 moles 5) Calculate the molar mass (Mr) of aspirin (C9H8O4) Carbon + Hydrogen + Oxygen = 180g/mol (12.01 x 9) (1.0079 x 8) (16 x 4) 108 8.06 64 6) Using this and the mass of aspirin obtained in your experiment, calculate the number of moles of aspirin produced (Actual Yield). Moles of aspirin = 1.07 = 0.00594mol 180 7) Calculate the percentage yield of your preparation. 1.07 x 100 = 24% 4.45 ?? ?? ?? ?? Nahom Efrem 16/06/2009 Synthesis of Aspirin ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Inorganic 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 AS and A Level Inorganic Chemistry essays

  1. Peer reviewed

    Deducing the quantity of acid in a solution

    5 star(s)

    By using the volume calculated previously and the moles of the acid, we can calculate the final concentration using the formula n/V = C. 2.5 x 10-03 moles of H2SO4/0.0202 dm3 = 0.124 mol/dm3 (3 s.f.)

  2. effects Concentration and Temperature on the Rate of Reaction

    I will use the following values: [BrO3] = 0.008 [Br -] = 0.01 [H+]2 = (0.1)2 = 0.01 At room temperature, I calculated the reaction rate for these values to be 0.0221seconds-1. I will now substitute the above values into the rate equation in order to calculate the constant 'k',

  1. ethanedioate complex of iron

    The solution was then titrated with the standard (approx. 0.01M) dichromate solution. Just before the end-point, the color of the solution was changed from colorless to grey-green; at this point the dichromate solution was added dropwise until the violet color persisted throughout the solution and this was taken as the end-point.

  2. Analysis of Aspirin tablets

    of tablets:3 Mass of aspirin tablets= 1.0181 g Rough 1 2 3 Final reading (cm3) 16.40 30.80 45.40 35.40 Initial reading (cm3) 1.30 16.40 31.00 20.90 Vol. of acid (cm3) 15.10 14.40 14.40 14.40 Observations When the aspirin was heated with sodium hydroxide, the aspirin tablets dissolved and only some white powder was left in the flask.

  1. Analysis of Commercial Aspirin Tablets

    The no. of moles of NaOH left after hydrolysis =0.05M*18.88 cm3*2*1/1000*10 =0.019mol 3. The no.

  2. Scientific Practical Techniques

    to set up the instrument precisely, although you have to know all spring are not the same, same spring are pre tensioned, this means that they coil up tight when not loaded. Therefore a minimum force must be applied to make them begin to stretch as a result they do

  1. Acid Content of Vinegar

    Calculate the cost of one gram of ethanoic acid in your brand of vinegar as a percentage by mass. The cost of one gram of ethanoic acid in Morrow vinegar is 7.56c. 5.87 grams in 100 grams 500�100= 5 5�5.87= 29.35 grams of ethanoic acid in 500ml of Morrow vinegar

  2. Fission and Fusion (Open Book paper 2008)

    If uncontrolled, fission will accelerate out of control due to more and more neutrons being given off. Nuclear reactors generate electricity using a mixture of 238U and 235U. 238U does not undergo fission; it absorbs neutrons, interrupting the chain reaction so helping to control it.

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