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Saturday, June 19, 2021 8:44 AM, , Til B.Sc, VI SEM Pap-VIl Lab Manual Maharani's science college for women, Bangalore., , Experiment No - 9, Preparation of cuprammonium sulphate and determination of 3... and hence CFSE, Aim: To Prepare cuprammonium sulphate complex, determination of dou. and crystal field splitting energy, of the complex, Principle: Cu’ ions of copper sulphate solution react with excess of ammonia to form a deep blue complex, Cuprammonium sulphate. The absorbance of this blue colored complex is measured at different wavelengths,, aux is Computed by graphical method. From the Planck’s equation AE = he/A, crystal field stabilization, , (splitting) energy can be calculated., Reaction:, , CuSO, + 4NH, ------> [Cu (NH))x] SOx, Procedure:, , Standard solution of copper sulphate containing Img cm’ of Cu’” is prepared by dissolving 400mg of, CuSO, SH,O crystals in a 100ml standard flask, Sem’ liquor ammonia is added to it and made up to the mark, by adding distilled water. An intense blue colored solution of cuprammonium sulphate results, The, absorbance of this solution is measured using different filters (wavelengths) in a spectrophotometer., , A plot of Absorbance vs Wavelength is drawn, the wavelength corresponding to the maximum absorbance, dows i8 recorded from the graph. From the du. value the crystal field stabilization (splitting) energy is, calculated using the equation, CFSE = hv = hee, later CFSE for one mole can be calculated by, multiplying the value with Avogadro number., , adsorbance, , eeceot, , A graph of Absorbance vs i, Result:, 1) Wavelength corresponding to maximum absorbance, deux, 2) Crystal field splitting energy (CFSE) of the complex, , , , om, Jmol, , , , 31, , , , , , , , , , , , , , , , , , , , , , , , , , Observations and calculations:, Trial No.| iinnm | Absorbance or O.D., 1, 2, 3, 4, 5, 6, Calculation of i...and CFSE:, From the graph, deux. = wavelength corresponding to maximum absorbance, , Crystal field splitting energy (CFSE) = hv = J, Where h = 6.634 x 10™J s,c =3x10'ms"., , , , 6.634 x 10™ x 3x10", CFSE = —————_______—, , danas, , = ~----——-- Joules —> Y., , CFSE for one mole of copper ions in the complex, [Cu (NH;),]"" = AN x Y, , = 6.023 x 10°x “*Y”, , ooo mol, , (Avogadro number, AN =6.023x107*)