Using a Buchner funnel, a hose, and a suction flask we created a vacuum filtrator which we used to help remove the remaining liquid on the copper so that we may make a more precise measurement of the mass of the remaining copper. Our final mass of copper was .7951 grams. Results and Discussion: Initial Mass of Cu: .25 grams When we mixed the 5 ml of 6 molar HNO3 the copper had disappeared, indicating it had been used in the reaction. The copper had undergone a single replacement reaction and a decomposition reaction. Initial equation: Cu(s) + HNO3(aq) -> Cu(NO3)2(aq) + NO2(g) +H2O(l) Balanced: Cu(s) + 4HNO3(aq) -> Cu(NO3)2(aq) + 2NO2(g) + 2H2O(l) The copper had replaced the Hydrogen in the HNO3 and the NO3 had also broken down into NO2 and O2- allowing the H+ to bond with it and create
The aspirator was turned to medium high, and then the copper was poured onto wetted filter paper. Using distilled water to remove all copper from the beaker. Once completely on filter paper 6mL of acetone was added to the copper to help dry it out. The filter paper was then removed and set down to dry completely. Once dry the filter paper was weighed with the copper on it and subtracted from the original weight to see the amount of copper left after
Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds. Then, add the supernatant into the boiling test tube and repeat this step one more time with another 1 mL of deionized water. Acquire a pair of metal test tube holders and heat the boiling test tube to evaporate the water for 15 minutes. Let is cool after and weigh it. Then, calculate a percent yield of zinc iodide and write a balanced chemical equation and determine the limiting
The R tube will then be put in a large beaker. Another large test tube, boiling tube will be needed, along with a Pasteur pipet. A regular sized test tube will be labeled “C” for “colored solution,” and the new boiling tube will be labeled “P” for “product”. One boiling chip will then be placed into the P tube. 5mL of acidified water will be measured, using a graduated cylinder, and will be transferred to the R tube, and will be immediately vigrously mixed with the reactants.
While stirring, 6 M NaOH was added drop-wise until the solution became basic, turning red litmus paper blue. A total of 3.84 mL NaOH was required to achieve this; the resulting solution appearing dark blue with cloudy precipitates. The solution was then heated gently atop a hot plate to catalyze the next reaction, with care taken to assure all residue was kept off the walls of the beaker. Heating continued until the reaction reached completion and the solution slowly changed from blue to a dark green and finally black. At this point the heat was turned off to allow the black solid in the beaker, CuO, to settle to the bottom.
Allow the mixture to cool for a few minutes then filter it, using either gravity or vacuum filtration. (We shall be using vacuum filtration.) Wash the residue in the funnel once with a little water and collect all the filtrate. 4. Pour all the filtrate and washings into a 250cm3 volumetric flask.
Lab 4 – Energy Sources and Alternative Energy Experiment 1: The Effects of Coal Mining |Table 1: pH of Water Samples | |Water Sample |Initial pH |Final pH (after 48 hours) | |Pyrite |.6pH |.7pH | |Activated Carbon |.6pH |.8pH | |Water |.6pH |.7pH | POST LAB QUESTIONS 1. Develop hypotheses predicting the effect of pyrite and coal (activated carbon) on the acidity of water? a. Pyrite hypothesis = If pyrite is added to water, then the acidity of the water is neutral. b. Coal (activated carbon) hypothesis = If coal or activated carbon is added to water then the acidity of water is basic.
Allow the splint to burn until the color fades. Don’t let any solids to fall into the burner. -Soak the wooden splint in the “rinse water” to put it out completely; move it to trash. -Record observations on flame color produced by the metallic salt in the Data Table. -Repeat above steps (middle section) for all metallic salts (five total).
(4 points) Problem 4: We need 1,000 electric drills per year. The ordering cost for these is $100 per order and the carrying cost is assumed to be 40% of the per unit cost. In orders of less than 120, drills cost $78; for orders of 120 or more, the cost drops to $50 per unit. Should we take advantage of the quantity discount? (4 points) Problem 5: George Heinrich uses 1,500 per year of a certain subassembly that has an annual holding cost of $45 per unit.
SciTronics had a total of $ 102,000 (75,000 + 27,000) of capital at year-end 2008 and earned before interest but after taxes (EBIAT) $ 16,120 (avg. tax rate = 38%) during 2008. Its return on capital was 15.8% in 2008 which represented an increase from the 8.7% earned in 2005. 4. SciTronics had $ 75,000 of owners’ equity and earned $ 14,000 after taxes in 2008.