Chemistry 2000B Spring 2002 Assignment 2 Due: Thursday, Feb. 7, noon 1. The half-life of 102 Tc is 5.3 s. How long would it take for 95% of the 102 Tc in a freshly prepared sample to decay? [5 marks] 2. Benzylpenicillin is an antibiotic which is commonly administered to farm animals to increase productivity by preventing the animals from contracting diseases while living in crowded conditions. Unfortunately, many humans are hypersensitive to penicillins. There has therefore been some concern over the presence of residues of this antibiotic in meat products. Fortunately, benzylpenicillin is not very heat stable. When meat is cooked in oil at 140 C, the half-life of benzylpenicillin is 45 min. At 180 C (a more common frying temperature), the half-life is 20 min. 1 Assume that the chemical decay process obeys first-order kinetics. (a) What are the activation energy and preexponential factor for the decay of benzylpenicillin? [8 marks] Note that since there are only two points, there is no need to use a graphical method. (b) Beef obtained from animals treated with benzylpenicillin typically contains approximately 13 mg of the
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