(6) experimental mass Ca pill- theoretical mass Ca pill x 100% %error theoretica
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(6) experimental mass Ca pill- theoretical mass Ca pill x 100% %error theoretical mass Ca pi Safety Considerations entire time that you I. Goggles and appropriate protective clothing must be worn during the or anyone else is performing an experiment in the laboratory. 2. Food or drink is never permitted in the laboratory at any time. created 3. Special care must be taken to avoid the bum hazards present in the hot surfaces by the hot plate. 4. Special care is necessary when using hydrochloric acid (HC) because it is toxic, corrosive, and can cause chemical burns to skin. If any hydrochloric acid solution contacts your skin, flush the affected area with water for five minutes and inform the 5. instructor. laboratory. Wash hands thoroughly with soap before leaving the Procedure specified by the 1. obtain a calcium supplement pill, note the calcium content as manufacturer, and record this value on your data sheet. Mass a piece weighing paper to the nearest mg (0.001 and record the value on your 2. data sheet. 3. Use forceps to transfer the calcium pill to the weighing paper, mass the weighing paper and its contents to the nearest mg (0.001 g), and record the value on your data sheet 4. obtain about 20 mL of 2.0 Mhydrochloric cid (HC) solution in a labeled, clean, dry 150 mL beaker for use throughout the experiment. 5. Use forceps to transfer the calcium pill to a clean, dry 150 mL beaker and then add 16-17 ml of 2.0 M HCI using a 50 mL graduated cylinder. Rinse the graduated cylinder with about 10 mL of distilled water two times. The rinse can be disposed by flushing it down the drain in the sink. 6. Use a clean glass stirring rod to break up the calcium pill as it dissolves which may take up to 5 min. After the evolution of carbon dioxide gas (Co2) ceases, place the beaker onExplanation / Answer
(1). 1. In the step 8 if small amount of Solid gets into the test tube, during centrifugation the undissolved matter settles at the bottom of test tube which can be eliminated. But while transfering from centrifuge tube care should be taken to decant liquid without the solid. If solid particles appear it affects the furthur processes.
(2) This procedural error would result in the increase in mass of calcium because the binders and fillers present in the calcium pill are undissolved matter which would increase the weight of Ca2+ ion.
(3) This procedural error would lead to incomplete formation of calcium carbonate or no formation of product at all. Without this step goin to step 15 is not recomended.
(4) To improve the seal between filter paper and funnel the outside corner is torn off and the piece is placed in the filter paper cone. This doesnt affect the Calcium ion mass.
(5) There will be error in the mass from wet to dry condition even when it is just a mark of wet fingerprint. Less of calcium ion mass may be observed.
(6) This procedural error would altogether affect the mass of the calcium ion . It may either increase or decrease depending the wieght of filter paper used.
3) To find out the percentage yield
Percentage yield = Actual yield× 100/ Theoritical yield
For a calcium pill 1250mg of calcium carbonate gives 500mg of elemental calcium
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