Rahul is a ten year old boy. He had purchased a packet of potato chips more than a month ago. Rahul opened the packet at the time but could eat only some of the potato chips from it. He then kept the open packet containing remaining potato chips on his book rack. He wanted to eat the remaining potato chips today. Just when Rahul was about to put these potato chips into his mouth, his elder sister Pavni, who is a student of class `X` entered the room. She found that these potato chips were giving unpleasant smell. When she put one potato chip in her mouth, it hat so unpleasant taste. Pavni took away the packet from Rahul and did not allow him to eat these potato chips. She threw away the potato chips into a dustibin.
(a) What is given to the condition in which potato chips kept open for a considerable time give out unpleasant smell and taste?
(b) Which chemical reaction is responsible for the soilage of potato chips kept exposed by Rahul for a considerable time?
(c) What produces the unpleasant smell as well as unpleasant taste in potato chips? Explain.
(d) With which gas the plastic bags containing potato chips are filled and then sealed by manufactures?
How does it help?
(e) What values are displayed by Pavni in this episode?

Explanation

(a) Rancidity.
(b) Oxiditation reaction.
(c) Potato chips contain oil. When the oil present in potato chips (which have been kept exposed for a considerable time) gets oxidised by the oxygen of air, its oxidation products have unpleasant smell and taste. The potato chips are then said to have turned rancid. They become unfit to eat. ltbr (d) The plastic bags containing potato chips are filled wiht nitrogen gas and then seald. When the potato chips are surrounded by an unreactive gas nitrogen, there is no oxygen (of air) in the plastic bag to cause oxidation of oil present in potato chips and make them rancid.
(e) The values displayed by Pavni are (i) Awareness (or knowledge) that oil and fat containing foods get spoiled on keeping exposed for a long time and become unfit to eath and (ii) Concern for the health of her brother (because she tasted the potato chips herself first and finding them racid, did not allow her brother to eat them).