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I concentrated HCI (drops) Discussion Bunsen burner Most chemical synthesis involves separation and purification of the desired product from unwanted side products. Some methods of separation, such as filtration, sedimentation, declaration, extraction, and sublimation were discussed earlier. This experiment is designed as a quantitative evaluation of your individual laboratory skills in carrying out some of these operations. At the same time you will become more acquainted faith two fundamental types of chemical reactions redo reactions and metathesis (double-displacement) sections.
By means of these reactions, you will finally recover the copper sample with maximum efficiency. The chemical reactions involved are the following. Cue(s) + 4 HON.(as) * NINE(g) + 2 H2O(l) Redo [1] -+- 2 Nah(as) Nanny(as) Metathesis [2] cue(s) * H2O(g) Dehydration [31 cue(s) HASPS(as) –3 cuscus(as) H2O(l) Metathesis [4] couscous) * Zen(s) azans(as) -t- CUE(S) Each of these reactions proceeds to completion. Metathesis reactions proceed to completion whenever one of the components is removed from the solution, such as in the formation of a gas or an insoluble precipitate driving forces).
This is the case for reaction [1], and [3], where in reactions [1] and [3] a gas and in reaction [2] an insoluble precipitate are formed, Reaction [5] proceeds to completion because zinc has a lower unionization energy or oxidation potential that copper. CHEMISTRY – INCH Lab: Reactions of Copper and Percent Yield Page 1 of 8 The objective in this experiment is to recover all of the copper you begin with in analytically pure form. This is the test of your laboratory skills. The percent yield of the copper can be expressed as the ratio of the recovered weight o initial weight, multiplied by 100: [pick Procedure ; Weight approximately 0. 00 g of no. 16 or no. 18 copper wire (1) to the nearest 0. 0001 g and place it in a 250 ml beaker. Add 4-5 ml Of concentrated HON. to the beaker, IN THE HOOD. After the reaction is complete, add 100 ml distilled H2O. Describe the reaction (6) as to color change, evolution Of gas, and change in temperature (exothermic or endothermic) in the report sheet. ; Add 30 ml of 3. 0 M Noah to the solution in your beaker and describe the reaction Add two or three boiling chips and carefully heat the solution while stirring tit a glass stirring rod just to the boiling point.
Describe the reaction on your report sheet Remove the boiling chips, ; Allow the black Coo to settle; then decant the supernatant liquid. Add about 200 ml of very hot the Coo to settle. Decant once more, What are you removing why washing and decanting (9)? Add IS ml of 6. 0 M HASPS. What copper compound is present in the beaker now (10)? Your instructor will tell you whether you should use zinc or aluminum for the reduction of Cue (II) in the following step. A. Zinc In the hood, add g of 30-mesh zinc metal all at once and stir until the appurtenant liquid is colorless.
Describe the reaction on your report sheet (11). What is present in solution (12)? When gas evolution has become very slow, heat the solution gently (but do not boil) and allow it to cool. What gas is formed in this reaction (13)? HOW do you know (14)? B. Aluminum In the hood, add several I-inch squares of aluminum foil and a few drops of concentrated HCI Continue to add pieces Of aluminum until the supernatant liquid is colorless. Describe the reaction on your report sheet (11). What is present in solution (12)? What gas is formed in this reaction (13)? How do you now (14)?