Chemistry TAS Report Essay

1. Experiment Number 10 2. Date 18/01/2008 3. Title finding of the labyrinthine sense ageless for the reaction Fe3+(aq) + SCN-(aq) <=> FeSCN2+(aq) 4. Aims/ accusive To determine the rest constant for the reaction Fe3+(aq) + SCN-(aq) <=> FeSCN2+(aq) 5. Introduction / Theory In this experiment, the equilibrium constant for the formation of a tortuous ion, FeSCN2+(aq), is determined. Complex ions, thiocyanatoiron(III) ions, be formed from iron(III) ions and thiocyanate ions in aqueous solution Fe3+(aq) + SCN-(aq) <=> FeSCN2+(aq) (1).see muchchemistry matriculation notes semester 1The equilibrium constant for this reaction isKc = FeSCN2+(aq) (2) Fe3+(aq)SCN-(aq) The harvest-home complex ion is the only one of the collar species which has an appreciable color (blood-red). 6. Relevant Equations/ chemical Reactions Involved Fe3+(aq) + SCN-(aq) <=> FeSCN2+(aq) 7. Chemicals 0. 002 M KSCN(aq) 50 cm3 0. 2 M Fe(NO3)3(aq) 20 cm3 8. Apparatus and equipment chan ge state underground 5 Dropper 2 10 cm3 measuring cylinder 1 Lamp 1 25 cm3 measuring cylinder 1 Wash bottle 1 Safety spectacle 1 250 cm3 beaker 1 9. map 1. 0. 2 M Fe(NO3)3(aq) was used and 10 cm3 of 0. 08 M, 0. 032 M, 0. 0128 M, 0. 00512 M Fe(NO3)3(aq) were prepared respectively.The solutions were added by utilise 10 cm3 measuring cylinder to 5 full-strength boiling subways in a rack as below. Tube zero(prenominal) 1 2 3 4 5 SCN-(aq) / cm3 10 10 10 10 10 Fe3+(aq) / cm3 10(0. 2 M) 10(0. 08 M) 10(0. 032 M) 10(0. 0128 M) 10(0. 00512 M) 3. Tubes 1 and 2 were wrapped around with a strip of paper so that wispy was excluded from the side. 4. The solutions towards the lamp were looked vertically down to compare the semblance ardor. 5. Some of the solution from the standard electron pipe 1 was outside with a dropper until the emblazon intensities of solutions in both pipages were the same. And the removed liquid was put into a clean and dry beaker.6. The judgment of the solu tion in thermionic tube 1 was then measured. 7. stairs 3 to 6 were repeated with tubes 1 and 3, 1and 4 and finally 1and 5. 10. Observations The blazon intensities of the solutions in the two tubes being sight were the same. 11. Data, deliberation and Results Height of solution in veritable tube 1 = 59 mm Height of solution in tube 1 having the same colour intensity as tubes 2, 3, 4 and 5 are Same colour intensity as 2 3 4 5 Height of solution in tube 1 (mm) 45 35 28 23 12. Conclusion The equilibrium constant for the reaction Fe3+(aq) + SCN-(aq) <=> FeSCN2+(aq) was found to be 82.1 M-1. 13. Discussion 1. By M1V1 = M2V2, For tube 1, sign preoccupation of SCN-(aq) = 0. 001 M initial tightfistedness of Fe3+(aq) = 0. 1 M For tube 2, initial tautness of SCN-(aq) = 0. 001 M initial concentration of Fe3+(aq) = 0. 04 M For tube 3, initial concentration of SCN-(aq) = 0. 001 M initial concentration of Fe3+(aq) = 0. 016 M For tube 4, initial concentration of SCN-(aq) = 0. 001 M initial concentration of Fe3+(aq) = 0. 0064 M For tube 5, initial concentration of SCN-(aq) = 0. 001 M initial concentration of Fe3+(aq) = 0. 00256 M 2.Concentration of FeSCN2+ in tube 1 = 0.001 M 3. balance of depth in the colour similitude with tube 2 = 45 /59 = 0. 763 Ratio of depth in the colour comparison with tube 3 = 35 /59 = 0. 593 Ratio of depth in the colour comparison with tube 4 = 28 /59 = 0. 475 Ratio of depth in the colour comparison with tube 5 = 23 /59 = 0. 390 balance wheel concentration of thiocyanoiron(III) ions In tube 2 = 0. 001 x (45 / 59) = 7. 63 x 10-4 M In tube 3 = 0. 001 x (35 / 59) = 5. 93 x 10-4 M In tube 4 = 0. 001 x (28 / 59) = 4. 75 x 10-4 M In tube 5 = 0. 001 x (23 / 59) = 3. 90 x 10-4 M 4. Fe3+equil = Fe3+initial FeSCN2+equil = 0. 04 7.63 x 10-4 = 0. 0392 M SCN-equil = SCN-initial FeSCN2+equil = 0. 001 -7. 63 x 10-4 = 2. 37 x 10-4 M 5. Room temperature = 16 oC K = FeSCN2+equil / (Fe3+equilSCN-equil) = 7. 63 x 10-4 / (0. 0392)(2. 37 x 10-4) = 82. 1 M-1 6. There are a couple of(prenominal) sources of mistake in this experiment. (1) Determination of colour intensity in the two tubes observed might not be accurate. (2) winning reading when measuring the depth of liquid. hallucination estimation When taking initial reading, error is + 0. 05 cm3. When taking final reading, error is besides + 0. 05 cm3. Therefore, error is + 0. 1 cm3.