Cathy
Lab Partners:
Chelsea
Brooke
Sept 4, 2012
Chemistry 131A
Dr. Vicki H Audia
Pelab Questions: Proposed procedure for separation of a mixture: Use physical properties of the 4 substances to separate.
1. Remove iron with magnet
2. Add water to the mixture to melt the benzoic acid and NaCl then filter out sand.
3. Chill the solution and scoop the acid out leaving a salt solution. 4. Boil water away leaving salt.
Purpose: The purpose of this lab is to learn separation techniques using individual physical properties of each substance in the mixture.
Procedure and Data Sheets: Flow Chart. Data Sheets attached. Instructions followed from Lab Manual pages 49-65
7.2706 g Mixture
7.2706 g Mixture
Mixture: Iron Filings, Sand, Benzoic Acid, NaCl
Mixture: Iron Filings, Sand, Benzoic Acid, NaCl
Extraction
Extraction
2.3027 g Iron Filings
2.3027 g Iron Filings
Iron Filings, Sand, Benzoic Acid, NaCl magnet
Iron Filings, Sand, Benzoic Acid, NaCl magnet
Decantation
Decantation
1.8298 g Sand
1.8298 g Sand
Sand, Benzoic Acid, NaCl Add 50 ml water and heat close to boiling
Sand, Benzoic Acid, NaCl Add 50 ml water and heat close to boiling
Filtration x 2
Filtration x 2
1.5517 g Benzoic Acid
1.5517 g Benzoic Acid
Benzoic Acid and NaCl solution ice bath
Benzoic Acid and NaCl solution ice bath
Evaporation
Evaporation
1.7326 g NaCl
1.7326 g NaCl
NaCl solutionhot plate
NaCl solutionhot plate
Observations: 1. Small white grains stuck on Fe filings after separation. 2. Crystals on the beaker and in the sand after decantation. Which may make the mass of the sand higher than it should be. Also on the glass stirring rod. Should have weighed the glass rod before and after the procedure. 3. While drying the sand we noted a popping of the sand in the bottom of the beaker. We quickly turned off the burner and allowed it to cool. 4. While