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Chemistry 121 Colligative Properties Lab Exhibition of Picked Calculations via Choice We Determination of Kf pertaining to Naphthalene To determine the Kf intended for naphthalene, we need to find the difference in the cold point of pure naphthalene and the remedy of 1, 4-dichlorobenzene in naphthalene. Let’s say that we did this kind of experiment, employed 1 . 00 g one particular, 4-dichlorobenzene in 10.

00 g naphthalene, and found which the freezing temperatures of natural naphthalene was 78. 2C, while those of the solution was 75. 4C. This gives all of us a? Tf of 79. 2C , 75. 4C = 2 . 8C.

Making use of the equation intended for freezing level depression and solving pertaining to Kf, we have,? Tf = Kfmsolute Kf sama dengan? Tf/msolute where msolute equals the molality of the solute. What is the molality with the solute? msolute=molality of solute = skin moles of solute/kg solvent moles of solute = 1 ) 00 g 1, 4-DCB/146. 9 g/mol = 6. 81 back button 10-3 skin moles 1, 4-DCB kg of solvent sama dengan 10. 00 g naphthalene/1000 g/kg = 0. 01 kg solvent msolute = 6. 81 x 10-3 moles one particular, 4-DCB/0. 01 kg naphthalene = zero. 681 meters Kf sama dengan 2 . 8C/0. 681 m = 5. 112 Kkg/mol The actual value for Kf for naphthalene is 7. 45 Kkg/mol, so jooxie is a fair quantity off the draw.

This is a rather crude research, so that’s to be expected. Determination of the Molecular Mass/Molecular Formula of Much needed Sulfur Even though this try things out didn’t move as well as I would have loved, there seemed to be some difficulties with the presentation of the info as they were obtained, therefore i thought I’d demonstrate how to do this calculation. Elemental sulfur contains a molecular formula of S8 (there are eight sulfur atoms in a molecule of sulfur, just like you will find 2 hydrogen atoms in a molecule of hydrogen). So , the purpose of this experiment really was just to observe how close you may come to this answer.