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

Preparation of Potassium Trioxalatoferrate (III)

Extracts from this document...


Preparation of Potassium Trioxalatoferrate (III) Introduction The aim of this experiment was to calculate the percentage yield in the preparation of crystals of potassium trioxalatoferrate (III). This contains the complex ion trioxalatoferrate which is made up of three oxalate ions (C2O42-) bonded to an iron (III) ion in an octahedral shape: 3- C2O4 C2O4 Fe C2O4 Trioxalatoferrate (III) Ion In this complex ion, the oxalate ions act as ligands. They act as ligands because each one of the negative oxalate ions donates 2 pairs of electrons in its bond to the iron ion making the oxalate ions chelating bidentate ligands. The preparation of potassium trioxalatoferrate (III) takes place in three stages. Firstly, ammonium iron (II) sulphate reacts with oxalic acid to give iron (II) oxalate and ammonium hydrogensulphate: (NH4)2Fe(SO4)2 (aq) + H2C2O4 (aq) --> FeC2O4 (s) + 2NH4HSO4 (aq) Then the iron (II) oxalate is reacted with hydrogen peroxide and potassium oxalate, producing potassium trioxalatoferrate (III) and iron (III) hydroxide: 6FeC2O4 (s) + 6K2C2O4 (aq) + 3H2O2 (aq) ...read more.


The liquid was decanted off and 50cm3 of hot deionised water was added to the precipitate. The mixture was stirred. After the precipitate had settled, the liquid was once again decanted off. 10cm3 of potassium oxalate solution was added to the washed precipitate and the mixture was heated to about 40oC. 20cm3 of "20 volume" hydrogen peroxide solution was added slowly with continuous stirring to the mixture. The temperature was kept close to 40oC during the addition of the hydrogen peroxide. This changed the colour from orange to dark red / brown. The mixture was heated nearly to boiling and oxalic acid solution was added, dropwise with stirring, until the brown precipitate of iron (III) hydroxide dissolved. The solution changed in colour from dark red / brown to clear lime green. The reaction mixture was kept near to boiling during the addition of the oxalic acid. The hot solution was filtered through a fluted filter paper into a crystallising basin. ...read more.


This results in possible errors in the balance and measuring cylinder, meaning the mass of hydrated ammonium iron (II) sulphate and the volume of oxalic acid, potassium oxalate, hydrogen peroxide, deionised water and ethanol could all be slightly wrong. If less of each compound was put in, the mass of potassium trioxalatoferrate (III) would not be as much as anticipated. There are more factors that result in the yield being less than 100%, including systematic errors. These include flaws in the equipment, flaws in the procedure (such as when the solution is transferred from the beaker to the crystallising basin some solution remains in the beaker) and lack of purity in reagents if they are not as concentrated as stated because some of it has reacted with air over a long period of time. Human error is also a major contributor to the yield not being 100%. In the preparation of potassium trioxalatoferrate, the hydrogen peroxide acts as the oxidising agent. ?? ?? ?? ?? 1 Lee McFadzean ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Aqueous 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 GCSE Aqueous Chemistry essays

  1. How much Iron (II) in 100 grams of Spinach Oleracea?

    Bonding in complexes is complicated, involving the electron pair form the ligand being shared with the central ion, thus ligands are known as electron donors (4) A colorimeter can be used in this experiment as Iron (II) Ammonium Sulphate (aq)

  2. In this experiment you will prepare a complex compound of iron, potassium trioxalatoferrate(III), K3Fe(C2O4)3. ...

    expected from complete conversion of the mass of iron(II) ammonium sulphate used. FeSO4(NH4)2SO4?6H2O ???? K3Fe(C2O4)3? 3H2O 391.8 490.8 Theoretical yield = x 490.8 = 9.395 (g) 2. Calculate the percentage yield in this exercise, i.e. the percentage of the theoretical yield that has actually been achieved. % yield = x 100% = % Questions for discussion: 1.

  1. The aim of this assignment is to produce 1-bromobutane in the laboratory and write ...

    (A high temperature may vaporise quickly the Butan-1-ol, which will decrease the yield. After the reaction, we removed the top funnel and distillation head from the top of the flask and the cooling bath from around the flask and dried the outside of the flask.

  2. The preparation of 1- Bromobutane

    Therefore, this will be produced in a fume cupboard, to be safe in case of any escapes. Implementing... Method After searching on the internet for a suitable method of preparing 1-Bromobutane I chose the most suitable one for me. I adjusted it slightly according to my own goals, such as a 70% yield and totally 10 g of 1-Bromobutane (product)

  1. Determining the purity of Iron Wool.

    Using the amount of hydrochloric acid and a balance experimental equation we can calculate the number of water molecules present. The molecular equation for the experiment is: Na2Co3(aq) + 2HCL(aq) 2NaCl(aq) + H2O(aq) + CO2(g) The above equation indicates that the base, sodium carbonate will react with the acid, hydrochloric

  2. The Estimation of Iron (II) and Iron (III) in a Mixture Containing Both.

    ( Be sure to remember which one is rough and which ones are accurate.) In this reaction it is only the Iron (II) that reacts with the KMnO4 allowing us to workout the mass of Iron (II). ( see later answers )

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