Preparation of Pure Diphenyl
Experiment 2 Date: 24 January 2006
Title : Crystallization of a Crude Sample
Objective : Preparation of pure diphenyl via crystallization of crude diphenyl dissolved in ethanol.
Structural Formula of Organic Substances Involved :
Diphenyl Ethanol
Apparatus : Round-bottom flask (100 mL), measuring cylinder (50 mL), conical flask (50 mL), filter flask, beaker (100 mL), stemless glass funnel, Hirsch funnel, capillary tube, long glass tube, watch glass, glass vial, water condenser, retort stand, retort clamps, spatula, cork stand, fluted filter paper, filter paper for Hirsch funnel, electronic weigh, electrothermal heater, oven, aspirator, electrothermal device to determine melting point.
Chemicals : Crude diphenyl (3.0 g), ethanol (20 mL), decolourising charcoal (1.0 g), boiling chips, ice
Procedure :
Crude diphenyl (3.0 g) is measured and obtained using a beaker and a laboratory electronic weigh. The crude diphenyl is then put into a quickfit flask, together with 2 to 3 pieces of boiling chips. Ethanol (5 mL) is measured using a measuring cylinder and poured into the flask. A vertical water condenser is fitted to the mouth of the flask, which is then heated with an electrothermal heater. Water is let to run throughout the condenser. Meanwhile, a piece of fluted filter paper is inserted into a stemless glass funnel in a beaker, which is later put in an oven to be heated. Ethanol (15 mL) is again measured using a measuring cylinder while decolourising charcoal (1.0 g) is weighed using the electronic weigh. When the mixture in the quickfit flask is dissolved completely, the heater is removed and the ethanol is added to the mixture followed by the decolourising charcoal. The mixture is then boiled under reflux for 10 – 15 minutes. The preheated glass funnel, beaker and fluted filter paper are taken out of the oven upon reaching 15 minutes while an ice bath is being prepared. The mixture in the quickfit flask is filtered by gravity
Title : Crystallization of a Crude Sample
Objective : Preparation of pure diphenyl via crystallization of crude diphenyl dissolved in ethanol.
Structural Formula of Organic Substances Involved :
Diphenyl Ethanol
Apparatus : Round-bottom flask (100 mL), measuring cylinder (50 mL), conical flask (50 mL), filter flask, beaker (100 mL), stemless glass funnel, Hirsch funnel, capillary tube, long glass tube, watch glass, glass vial, water condenser, retort stand, retort clamps, spatula, cork stand, fluted filter paper, filter paper for Hirsch funnel, electronic weigh, electrothermal heater, oven, aspirator, electrothermal device to determine melting point.
Chemicals : Crude diphenyl (3.0 g), ethanol (20 mL), decolourising charcoal (1.0 g), boiling chips, ice
Procedure :
Crude diphenyl (3.0 g) is measured and obtained using a beaker and a laboratory electronic weigh. The crude diphenyl is then put into a quickfit flask, together with 2 to 3 pieces of boiling chips. Ethanol (5 mL) is measured using a measuring cylinder and poured into the flask. A vertical water condenser is fitted to the mouth of the flask, which is then heated with an electrothermal heater. Water is let to run throughout the condenser. Meanwhile, a piece of fluted filter paper is inserted into a stemless glass funnel in a beaker, which is later put in an oven to be heated. Ethanol (15 mL) is again measured using a measuring cylinder while decolourising charcoal (1.0 g) is weighed using the electronic weigh. When the mixture in the quickfit flask is dissolved completely, the heater is removed and the ethanol is added to the mixture followed by the decolourising charcoal. The mixture is then boiled under reflux for 10 – 15 minutes. The preheated glass funnel, beaker and fluted filter paper are taken out of the oven upon reaching 15 minutes while an ice bath is being prepared. The mixture in the quickfit flask is filtered by gravity
References: : Ault, Addison (1976), “Techniques and Experiments for Organic Chemistry” 2nd ed. Boston: Hollorook Press, Inc., 23, 79. Belloli, Robert C. (1974) “Organic Chemistry Experiments: Fundamentals of Organic Chemistry” 1st ed. United States of America: McGraw – Hill, Inc., 13, 16. Brieger, Gottfried (1969), “ A Laboratory Manual for Modern Organic Chemistry” 1st ed. New York: Harper & Row, Publishers, 14 – 19, 182. Pavia, Donald L., Lanpman, Gary M., Kviz, George S., Jr. (1976) “Introduction to Organic Laboratory Techniques” 1st ed. Philadelphia: W.B Saunders Corp., 493 – 513, 517. Sacks, Lawrence J. (1971), “Experimental Chemistry” 1st ed. New York: The Macmillan Company, 40, 208 – 209.