Question

Concentrated nitric acid is used in a test to detect adulteration of:
A.Cooking oil
B.Milk
C.Salt
D.Tea powder

Answer 1

Hint: We know that adulteration food (contamination of food) materials by adding a few substances to increase the quantity of material which are collectively called the adulterants.

Complete answer:
-As we know that milk consists of fat, proteins, lactose, water, and minerals adulterant by starch. To detect the presence of starch in milk, add a few drops of tincture of iodine appearance of a blue color that indicates the presence of starch. In this test the concentrated nitric acid is not used. Therefore, the option B is incorrect.
-We have to remember that the table salts are consisting of a minimum amount of iodine, called iodinated salt. Salt is adulterated by non-iodinated salt. In this test the concentrated nitric acid is not used. Therefore, the option C is incorrect.
Similarly, tea leaves are of inferior quality or which were damaged during the manufacturing process it will adulterate by various coloring agents to enhance the looks and price. Treating processed tea leaves that are adulterated by Prussian blue, indigo or turmeric, etc. Rub them between palms, smell them or dissolve them in water to detect sawdust or brick powder.
In this test the concentrated nitric acid is not used. Therefore, the option D is incorrect.
-We must remember that the cooking oil is a non-polar chemical substance which is hygroscopic in nature. The food which adulterated is unwholesome food, unsafe, or impure. Cooking oil is adulterated with argemone oil.
-To detect adulterant the argemone oil in cooking oil, or fat, take a few quantities of oil in a test tube and equal quantity of concentrated nitric acid and shake well. Red color to reddish-brown color in the below layer would indicate. If the red color or reddish-brown color shows in the acid layer, then it is adulterated with argemone oil. In the detection of adulteration oil we use concentrated nitric acid.
Therefore, the option A is correct.

Note:
-The food which adulterated is unwholesome food and unsafe.
-Iodine deficiency in humans, which can lead to swollen thyroid glands in the neck and dwarfism.
-The turmeric powder sawdust, chalk dust and yellow dye are adulterated with it which causes cancer and stomach disorders.
-In pepper, the dried papaya seeds are adulterated with it which causes allergy.