Materials Used in the Preparation of Substances like Soap, Glass, Ink, Paper, Cement, Paints, Safety Matches and Gun-Powder NDA Questions

NDA Chemistry

Materials Used in the Preparation of Substances like Soap, Glass, Ink, Paper, Cement, Paints, Safety Matches and Gun-Powder MCQ Questions


1.
Chemically, soap is best described as the:
A.
Ester of glycerol and a long chain fatty acid
B.
Potassium salt of an aromatic carboxylic acid
C.
Sodium or potassium salt of a long chain fatty acid
D.
Sodium salt of a long chain sulphonic acid
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ANSWER :
C. Sodium or potassium salt of a long chain fatty acid
2.
Soap is manufactured by the hydrolysis of oils/fats with caustic soda. This reaction is known as:
A.
Esterification
B.
Saponification
C.
Sulphonation
D.
Hydrogenation
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ANSWER :
B. Saponification
3.
Which by-product, useful in cosmetics, is obtained during the manufacture of soap from oils and fats?
A.
Glycerol
B.
Formaldehyde
C.
Stearic acid
D.
Ethylene glycol
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ANSWER :
A. Glycerol
4.
Soap fails to lather/form foam in hard water because it forms:
A.
An insoluble scum of calcium and magnesium salts of fatty acids
B.
A gel with silica present in hard water
C.
A soluble complex with calcium and magnesium ions
D.
A precipitate of sodium chloride
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ANSWER :
A. An insoluble scum of calcium and magnesium salts of fatty acids
5.
Shaving soaps are prepared to have excessive lather and to prevent them from drying quickly by adding:
A.
Titanium dioxide and starch
B.
Borax and sodium silicate
C.
Sodium chloride and sodium rosinate
D.
Glycerol and using potassium salts of fatty acids
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ANSWER :
D. Glycerol and using potassium salts of fatty acids
6.
Soft soaps used for medicinal and shaving purposes are generally the salts of fatty acids with:
A.
Potassium hydroxide
B.
Sodium hydroxide
C.
Ammonium hydroxide
D.
Calcium hydroxide
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ANSWER :
A. Potassium hydroxide