Prelaboratory preparation: Read pages 1 – 30 and 45 – 54 of the lab text. You may disregard the microscale distillation procedures of TECH 0704. Answer in your laboratory notebook the Safety Quiz on pages 11 – 12 and the Prelab Questions 1, 2a, 2b, 3 -5, pp. 67 - 68. EXPERIMENT: TECH 0704, Distillation, macroscale technique only, simple and fractional: Substitute a mixture of 25 mL ethanol and 25 mL water for the toluene/cyclohexane mixture.
Mixed Solutions: If 1 mmole of glucose (180mg=1mOsm) and 1 mmole of NaCl (58mg=2mmOsm) are put into a beaker and distilled water added to make 1 liter, the osmolarity is 3 mOSm/L. OSMOSIS CALCULATIONS: 1. Calculate the number of grams of NaCl needed to prepare 100 mL of a 280mOsm.L Solution. (280mosm/l) *(1L/1000mL)*(100mm/1)*(29mg/1mosm)*(1g/1000mg)=0.812g 2. Calculate the number of grams of glucose needed to prepare 100mL of a 280 msm/L glucose solution.
Juliana Park Mayumi Tamada CHEM 111B LAB/ M-F 1-4PM 15 August 2012 Spectroscopy Lab Introduction In this lab, the molar absorptivity of the complex FeLn2+ will be determined by using the absorbance of the complex and its concentration. The absorbance will be found by using a spectrophotometer. For the next part of the lab, the formula of the complex will be determined by also using the volume of ligand and the absorbance again. Experimental There are two different parts to the experiement. In the first part, five 100 mL flasks of 5 mL ligand solution, 5 mL 2 M sodium acetate, 4 mL 3 M NH2OH, and 1-5 mL Fe2+ solution are diluted with water.
Step 2. Heat test tube until all of the O2 has evolved Step 3. Record the amount of O2 produced Observations Mass of O2 produced: 3.915576 grams or .1224 moles Mass of KCl produced: 6.083363 grams or .0816 moles Calculations Chemical Reaction 2KClO3-> 2KCl + 3O2 Theoretical Yield (96/245.1)*10 grams= 3.916 grams of O2 Percent Yield 3.915576/3.916= .99989 *100= 99.998 percent Data Actual amount of Oxygen Produced |3.915576 grams | |Theoretical amount of oxygen Produced |3.916 grams of O2 | |The Percent Yield |99.998 percent | | Results The amount of oxygen produced was almost exactly what was expected with a percent yield of 99.998 percent. The Law of conservation of mass was also up held with there being a combined mass of 10 grams from the resulting O2 and KCl. Conclusion 10 Grams of Potassium chlorate when decomposed produces 3.915576 grams oxygen gas and 6.083363 grams potassium chloride Atomic Weight of Magnesium Introduction In this lab we will determine the atomic weight of magnesium by measuring the amount of hydrogen gas evolved when hydrochloric acid reacts with magnesium.
Slowly add the water mixed with oil and stir over medium heat until mixture thickens to dough. Let cool a few minutes and then knead until smooth. Kool-Aid Play dough with Alum (Nonedible) Alum is a pickling spice found in the spice section of your grocery store. It makes the play dough last longer. • 2, 1/2 cups flour • ½ cup salt • 1 Tbsp Alum • 1 package unsweetened Kool-Aid (6 g Pkg.)
100. g Al reacts with excess O2 to produce 150. g Al2O3 according to Calculate the theoretical and percentage yield. 4Al + 302 → 2 Al2O3. 79.4 % 14. Calculate the energy produced by the complete reaction of 150. g H2. 2H2 + O2 → 2H2O + 130KJ 4.83 x 103 kJ 15.
A voltmeter was used to measure the electrical resistance of different solutions. * Experiment and Observation: The plastic and glassware used in this experiment was thoroughly washed with hot water and rinsed with distilled water. * * Part I: Preparation of Standard Phosphate Solutions 1. 1.0 ppm standard: 1.00 mL of 10.0 ppm phosphate solution was placed in a 25 mL graduated cylinder and diluted to exactly the 10 mL mark with distilled water then poured into a plastic cup labeled 1. Cylinder was rinsed with distilled water.
After the penny is finished reacting, using the tongs, remove the penny. 9. Wash off the penny in tap water carefully and thoroughly. You will be holding the pennies with your fingers and if you still have acid in or on them, it can be uncomfortable. 10.
5) Swirled the solution until the NaEDTA (s) dissolved entirely. 6) After dissolving the solid, deionized water was added to the volumetric flask to make 250mL of EDTA solution. 7) This solution (from Step 6) was then transferred to a clean 250 mL Erlenmeyer flask and placed inside the desk for safe keeping; using a cork wrapped tightly in Parafilm. The disassociation of NaEDTA in water is expressed by the following equation: Na2H2EDTA (s) + H2O (l) yields EDTA4- (aq) + 2Na+(aq) + 2H+(aq) Na2H2EDTA (s) has a molar mass of 372.24 g/mol. Procedure - Reacting EDTA with your Zinc ion in Zinc Iodine Purpose; The
Obtain 6 clean/dry test tubes and arrange in your test tube rack. Label the test tubes 1,2,3,4,5,&6 6a. Test tube 1: Add 5 drops of Barium nitrate solution. Test 2: Add 3 drops of Sodium chromate solution. Combine test tubes 1 and 2 into one test tube (pour test tube into test tube 1).