1. Edible oil is not allowed to stand for a long time in air.
Ans.
i. When edible oils are left exposed to air for long period of time, they become rancid (i.e. the oils get oxidized.)
ii. Rancid oils have a foul odour and unpleasant taste.
iii. Thus, rancid oil is of no use.
iv. Edible oils is not allowed to stand exposed to air for long to avoid rancidity.