Chemistry Experiment Essay

456 Words2 Pages
Aim of the experiment: Estimation of Fe2+ from the given Mohr’s salt sample permanganometrically-(Redox titration). Theory: In a chemical reaction, oxidation and reduction occur simultaneously. Oxidation is defined as the loss of one or more electrons and the reduction is the gain of electrons by atoms or ions. In a redox reaction, a reducing agent is titrated against an oxidizing agent or vive-versa. All permangenometric methods are based on the oxidizing action of potassium permanganate. In sulphuric acid medium, potassium permanganate act as a strong oxidizing agent and the partial ionic equation is represented as- MnO4- + 8H+ + 5e- Mn2+ + 4H2O Here, heptavalent manganese (MnO4-) is reduced to the bivalent manganous (Mn2+) state. Estimation of iron means determination of the amount of iron present in 1 Litre of the given Mohr’s salt solution by standardized KMnO4. The redox reaction occurring during the titration is given below:- MnO4 + 5e- + 8H+ Mn2+ + 5Fe3+ + 4H2O Apparatus required: a) Beaker(100ml) b) Burette c) Pipette(10ml) d) Conical flask(250ml) e) Thermometer Procedure: 1) Standardization of KMnO4 solution:- This process involves the following steps:- i. 10ml of oxalic acid is taken in the 250ml conical flask. ii. 1/3TT of conc. H2SO4 is added to it. iii. A little amount of water is added. iv. This mixture is heated to 600C-700C. v. Then it is titrated against KMnO4 taken in the burette. vi. At the end point, the solution will turn into pale pink colour and at this moment, addition of KMnO4 should be stopped. Table 1:- Obs.No. | Volume ofOxalic acid | Burette reading(ml) | Mean reading(ml) | Strength ofOxalic acid(N) | | | Initial | Final | Difference | | | 1 | 10 | | | | | | 2 | 10 | | | | | | 3 | 10
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