Group Number 1
I. Title: Mass of the Reactants and Products
1. Measure amounts of reactants for a chemical reactions and place them in a closed system 2. Determine the mass of the system after reaction and verify that the mass is the same as that measured for the system before reaction III. Problem: How is mass conserved in a chemical reaction?
IV. Hypothesis: The mass before and after a chemical reaction will be the same as mass is conserved.
NOTE: Before anything else, make sure to wear your lab gown and safety goggles while conducting the experiment. Also keep in mind at all times the different laboratory safety precautions discussed to avoid laboratory incidents.
First, find the mass of the erlenmeyer flask, the test tube and the rubber stopper collectively. Record this as the mass of the empty space. Second, measure 20 mL of the potassium iodide solution using the graduated cylinder. Then, pour the solution into the erlenmeyer flask. Third, clean the graduated cylinder thoroughly and rinse it well with distilled water. Fourth, measure 10 mL of lead nitrate and pour this solution into the small test tube. Fifth, carefully place the test tube containing the lead nitrate solution into the erlenmeyer flask, being careful not to mix the solutions. Then, stopper the flask. Sixth, record the appearance of each of the solutions. Seventh, find the mass of the system containing the two solutions, then, record the mass in your table as the mass before mixing. Eight, with your hand keeping the stopper in place, carefully tip the system so that the solution in the test tube mixes with the solution in the flask. Don't forget to record your observations. Ninth, find the mass of the system once again. Then, record this as the mass after mixing. Last, remove the test tube from the system, pour the contents of the flask into the filter paper provided by your teacher. Try to get as much of the solid as possible into the filter....
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