Rrl Compound Mixture Separation.docx

Calcium carbonate and Sodium Chloride According to Schaller, other salts dissolve in water but some dissolve more easily. One could easily dissolve about 360 g of table salt in a liter of water, but the solubility of calcium carbonate is only about 0.01 grams per liter because the ions in sodium chloride, Na+ and Cl-, have lower charges than the ions in calcium carbonate, Ca2+ and CO32-. The higher the charges on the ions, the stronger their electrostatic attraction for each other, and the harder it is for the water to pull them apart. According to ScienceLearn, calcium carbonate has a very low solubility in pure water (15 mg/L at 25°C), but in rainwater saturated with carbon dioxide, its solubility increases due to the formation of more soluble calcium bicarbonate. Calcium carbonate’s solubility increases as the temperature of the water decreases. According to Haynes, the solubility of sodium chloride in pure water is very high in which it is 36.0 g/100 g of water at 25 degrees Celsius. According to O’Neil, one gram of sodium chloride dissolves in 2.8 mL of water at 25 degrees Celsius. Benzoic Acid According to Yalkowsky and Dannenfelser (1992), the water solubility of benzoic acid is 3400 mg/L at room temperature. According to Seidell & Linke (1952), its water solubility is 3.4 g/L at 25 degrees Celsius. According to University of Toronto – Chemistry Department, recrystallization of benzoic acid can be done with the microscale technique of sublimation.

References: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 94th Edition. CRC Press LLC, Boca Raton: FL 2013-2014, p. 4-89 O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 1596 Seidell, Atherton; Linke, William F. (1952). Solubilities of Inorganic and Organic Compounds. Van Nostrand. Retrieved 2014-05-29. University Of Toronto – Chem. Dept. Benzoic acid (microscale procedure). Recrystallization [PDF]. Retrieved from http://www.chem.utoronto.ca/coursenotes/CHM249/Recrystallization.pdf. pg 4-5 Yalkowsky, S.H. & Dannenfelser, R.M. (1992) Benzoic Acid. The Handbook of Aqueous Solubility.