pyridinium hydrobromide perbromide type of stationary phase column length column temperature rate flow of the carrier gas List the 4 general factors that affect the separation obtained on a gas chromatograph What specific technique is used to collect/isolate your purified unknown compound at the end of the recrystallization experiment? suction filtration 14 of 22 4/16/12 9:15 PM StudyBlue Flashcard Printing of Lab Final 2211L UGA
Name: Patrick Morefield Date: December 06, 2006 Lab Partner: Gabriel Rodriguez Unknown No. : 941 Report Sheet Colligative Properties: Freezing-Point Depression and Molar Mass |1. |Volume of cyclohexane |10..1mL | |2. |Mass of empty insulated test tube and spin bar |345.47g | | |Mass of stir bar, tube and cyclohexane |353.10g | | |Mass of cyclohexane |7.63g | |3. |Mass of insulated test tube, spin bar, cyclohexane and |353.25g | | |unknown | | |4.
54Cr 24 g. 52Cr 24 f. e. 14C 6 d. 50Cr 24 c. 12C 6 b. 63Cu 29 a. 17O 8 Copyright © Glencoe/McGraw-Hill, a division of the McGraw-Hill Companies, Inc. Chemistry: Matter and Change • Chapter 4 Mass contribution ( ؍mass)(percent abundance) For 27X: (27.977 amu)(92.23%) 08.52 ؍amu For 28X: (28.976 amu)(4.67%) 53.1 ؍amu For 29X: (29.974 amu)(3.10%) 929.0 ؍amu Atomic mass of X 08.52 ؍amu ؉ 1.35 amu ؉ 0.929 amu 80.82 ؍amu The element is silicon. Mass (amu) Isotope element. Show all your work.
Warm up questions: Exercise1： mass of ZnI2 is 2.56g The molar mass of ZnI2 is 319.18 g/mol The mole of ZnI2: 2.56g/319.18g/mol=0.00802mol 0.00802mol/(500*10-3L)=0.01604M 0.01604M ZnI2 should appear on the label of the flask. Exercise 2: Student 1: 0.43g zinc iodide The mole of ZnI2: 0.43g/319.18 g/mol= 0.00135mol 0.00135mol/0.01604M=0.084L 0.084L*(1000mL/1L)=84mL Student 2: 5.0*10-4 moles of zinc iodide. 5.0*10-4mole/0.01604M=0.031L 0.031L*(1000mL/1L)=31mL Molarity as a Concentration Unit Exercise 3: a. 2.56g ZnI2/500 mL of solution 2.56g/319.18 g/mol=0.00802mol 0.00802mol/(500*10-3L)=0.016M b. 0.00512g ZnI2/mL of solution 0.00512g/319.18 g/mol=1.6*10-5 mol 1.6*10-5 mol/(1*10-3L)=0.016M c. 0.00806 moles of ZnI2/500 mL of solution 0.00806mol/(500*10-3)L=0.016M d. 0.0161 moles of ZnI2/L of solution 0.0161mol/1L=0.016M Exercise 4: a.
In the beginning of the lab, two solutions were mixed, one had 1.87g of NaI and the other had 4.14g of Pb(NO3)2, both mixed separately with distilled water. But, when NaI and Pb(NO3)2, were weighed out they must have been off weigh, therefore resulting in the percent yield being so
The following mistakes were made when carrying out the experiment. What effect does each have on the calculated molar mass? Be specific. For example, too large because… Only part of the pipet was immersed in the boiling water, so the temperature in part of the pipet was less than that of the water bath. If the temperature was less than the water bath in some places because only part of the pipet was immersed in the boiling water, the molar mass calculated would become lower.
Some might think that by squeezing the bottle, Mr. Squiddy would go up with the water however, he would go down due to the pipette being used. The pipette had a little air bubble at the top of it, when the bottle was squeezed the water filled into the pipette creating an increase in pressure and a subsequently decrease in volume causing Mr. Squiddy to sink. When released, the high pressure subsided and he floated back up. In the crushing cans demo the cans were heated up with a little water inside and set to boil until steam appeared. Once the can was hot enough it was quickly placed in a bowl of ice cold water and the can crushed itself.
EXPERIMENT 11 Molar Mass of a Volatile Liquid DATA Run | UNKNOW | Mass of flask and foil(g) | 90.085g | Mass of flask and foil and condensed vapor (g) | 90.640g | Temperature of boiling water (˚C ) | 98˚C | Barometric pressure (torr) | 761mm Hg | Volume of flask (mL) | 140 mL | RESULTS Mass of unknown ( condensed vapor) | 0.555g | Volume of flask (vapor)(L) | 0.14 L | Temperature of vapor(k) | 371K | Molar mass of unknown (g/mole) | 118.380 g/mole | Advance Study Assignment 1) How would each of the following errors affect the outcome of this experiment? Would it make the molar mass high or low? Give your reasoning in three sentences or less in each case. a) The hole in the aluminum foil was quite large. if you were to have a larger hole in your aluminum cap, you would be losing vapor to the room.
There are two parts to this lab. Part 1 which will be a known hydrate CoCl2 ∙6H2O or Cobalt (II) Chloride hexahydrate, and Part 2 which will be an unknown hydrate. Equations and Mechanisms * Moles of hydrate and water ratio: Moles of water Moles
Aim : a) To determine reduction potentials of several redox couples. b) To determine the effect of concentration changes on cell potential. c) To determine the molar concentration of Cu2+ in the unknown using Nernst equation. Procedure : Please refer to the laboratory manual page 77 – 79. Results : Reduction Potentials of Several Redox Couples Galvanic Cell Measured Ecell Anode Equation for Anode Reaction Cathode Equation for Cathode Reaction Cu-Zn +1.19 V Zn Zn → Zn2+ + 2e- Cu Cu2+ + 2e- → Cu Cu-Mg +3.23 V Mg Mg → Mg2+ + 2e- Cu Cu2+ + 2e- → Cu Cu-Fe +0.89 V Fe Fe → Fe2+ + 2e- Cu Cu2+ + 2e- → Cu Zn-Mg +2.00 V Mg Mg → Mg2+ + 2e- Zn Zn2+ + 2e- → Zn Fe-Mg +1.54 V Mg Mg → Mg2+ + 2e Fe Fe2+ + 2e → Fe Zn-Fe +0.29 V Zn Zn → Zn2+ + 2e- Fe Fe2+ + 2e- → Fe Balanced net reaction Cu-Zn Zn (s) + Cu2+ (aq) → Zn2+ (aq) + Cu (s) Cu-Mg Mg (s) + Cu2+ (aq) → Mg2+ (aq) + Cu (s) Cu-Fe Fe (s) + Cu2+ (aq) → Fe2+ (aq) + Cu (s) Zn-Mg Mg (s) + Zn2+ (aq) → Mg2+ (aq) + Zn (s) Fe-Mg Mg (s) + Fe2+ (aq) → Mg2+ (aq) + Fe (s) Zn-Fe Zn (s) + Fe2+ (aq) → Zn2+ (aq) + Fe (s) Zn-Mg = + 2.00 V, Mg-Cu = + 3.23 V The cell potential of Zn-Cu = 3.23 V – 2.00 V = 1.23 V The measured cell potential of Zn-Cu = +1.19 V The value of the sum of the Zn-Mg and Zn-Cu cell potentials are nearly the same as the Cu-Mg cell potential.