1. Experiment 8: Gravimetric Analysis (In CHE116 Packet) 1CHE116

2. Purpose of This Experiment To determine the identity of an unknown sample Work in groups of 2, each group gets 1 unknown sample 2CHE116

3. Today in Lab Use the scoop provided to remove solid material from the reagent bottle (the italicized procedure steps will not be done) Each person in the group should work with a trial of the unknown sample CHE1163

4. General Approach to Experiment The unknown sample will be either Li 2 CO 3, Na 2 CO 3, or K 2 CO 3. These alkali metal carbonates are soluble in water. 1.Dissolve an aliquot of your sample in water 2. Add in CaCl 2 (aq) and mix well 3.Filter to isolate the CaCO 3 precipitate 4.Dry and weigh precipitate, calculate moles CaCO 3 made 5.Determine identity alkali metal carbonate by calculating g/mole of original unknown CHE1164

5. Filtering Figure 8.1 in your lab manual details the technique of filtering CHE1165 R.F. Schneider Wordpress OhioStateChemistry

6. Drying Oven Dry your filter paper and sample in the drying oven Make sure you know which sample is yours. Pencil does not wash off CHE1166

7. Additional Comments Data Table, line b, Mass of filter paper Weigh the empty filter paper after you have torn off the corner and marked it with pencil. Unknown number Make sure you record the number of your unknown CHE1167