1 (a)State one advantage and one disadvantage of corrosion.
(b) State the various methods for preventing rancidity of food.
a) DISADVANTAGES OF CORROSION — 1. Weakens material due to prolonged corrosive action. 2. loss, contamination, and deterioration of the appearance of a material. 3. safety, health and environmental risks due to corrosion, especially in manufacturing plants. 4. Corrosion tends to vent in technical malfunctions in machines.
ADVANTAGES OF CORROSION — 1. Corrosion of a material has to be renewed, thus giving scope of continuous demand for materials. 2. Corrosion becomes advantageous when a surface produces an oxide film that will keep corrosion from proceeding further; which happens to aluminum metal.
b) The various methods of preventing or retarding rancidity of food are as follows.
1.Rancidity can be prevented by storing foods away from light. In the absence of light the oxidation process of fats and oils slows down and thus rancidity is retarded.
2.Rancidity can be prevented by adding antioxidants to foods containing fats and oils. When antioxidants are added to foods then the fats and oils present in them do not get oxidized easily and hence do not turn rancid and the foods remain good to eat for a much longer duration.
3. Rancidity can be prevented by storing food in air tight containers because in airtight containers there is little exposure to oxygen then oxidation of fats and oils present in food is slowed down and thus rancidity is retarded.
4. Rancidity can be prevented by keeping food in a refrigerator because in a refrigerator when the food is kept the oxidation of fats and oils in it is slowed down due to low temperature and thus rancidity is retarded.
5. Rancidity can be prevented by packaging fat and oil containing foods in Nitrogen gas because the packed food is surrounded by a nitrogen gas which is a unreactive gas and there is no oxygen or air to cause its oxidation and make it rancid.