Chemistry (Part-VII)

11. Viscose fiber is obtained from: [S.S.C. Online CGL (T-I) 13.08.2021]

(a) cellulose
(b) coal
(c) oil
(d) petrochemicals

Correct Answer: (a) cellulose

Solution:Cellulose - Viscose is a regenerated cellulose fiber. It is produced by chemically treating cellulose, typically obtained from wood pulp or cotton linters, to create a soluble compound that is then forced through spinnerets to form fibers.

12. Incomplete combustion of fuels such petrol and diesel gives _______ . [S.S.C. Online CHSL (T-I) 15.03.2018]

(a) carbon dioxide
(b) carbon monoxide
(c) nitric oxide
(d) nitrogen dioxide

Correct Answer: (b) carbon monoxide

Solution:Carbon monoxide - Incomplete combustion occurs when there is not enough oxygen to burn the fuel completely. In the case of petrol and diesel (hydrocarbons), incomplete combustion leads to the formation of carbon monoxide (CO), a toxic gas, instead of carbon dioxide (

CO₂

13. Clothes made of _____ do not fold easily. [S.S.C. Online Graduate Level (T-I) 22.08.2017]

(a) Cotton
(b) Jute
(c) Silk
(d) Polyester

Correct Answer: (d) Polyester

Solution:Polyester - Clothes made of polyester are known for their wrinkle resistance. Polyester fibers are synthetic polymers that tend to retain their shape and do not fold or crease easily compared to natural fibers like cotton, jute, and silk.

14. Plastic bottles are made of a polymer called PET. The expanded form of PET is _______ . [S.S.C. Online CHSL (T-I) 24.01.2017]

(a) Polyethylene Terephthalate
(b) Polyethyl Terelene
(c) Polyethylene Triphosphate
(d) Polyethyl Tetrachloride

Correct Answer: (a) Polyethylene Terephthalate

Solution:Polyethylene terephthalate is a very common thermoplastic. It is a resin of the polyester family, which is used to make synthetic fibers, plastic bottles, etc. Its chemical formula is (C₁₀H₈O₄)n.

15. Electric wires are generally coated with which materials? [S.S.C. JE Mechanical Exam 27.10.2020]

(a) Polyethylene
(b) Polyurethane
(c) Polyvinyl chloride
(d) Polypropylene

Correct Answer: (c) Polyvinyl chloride

Solution:Polyvinyl chloride - Electric wires are commonly coated with polyvinyl chloride (PVC) due to its good electrical insulation properties, flexibility, durability, and flame resistance. Polyethylene, polyurethane, and polypropylene are also used for insulation in some applications but PVC is very common.

16. Which of the following is an natural organic compound? [S.S.C. Online Stenographer 14.09.2017]

(a) Nylon
(b) Plastic
(c) Wool
(d) Polythene bags

Correct Answer: (c) Wool

Solution:Wool is a natural organic compound (a protein). It is basically a fibrous protein, which is released from special types of cells. After cotton, wool is the most important organic compound.

Nylon is a synthetic polyamide, which is an organic compound containing carbon, hydrogen, oxygen, and nitrogen atoms arranged in specific structures.

17. Which of the following is synthetic rubber? [S.S.C. Online CHSL (T-I) 20.01.2017]

(a) Leoprene
(b) Monoprene
(c) Neoprene
(d) Isoprene

Correct Answer: (c) Neoprene

Solution:Neoprene rubber is a synthetic rubber, obtained by polymerization of chloroprene. This rubber, being chemically inert, can be used for a variety of industrial uses. It is also a fire retardant. Diving suits used by divers are also made with its help.

18. Terylene is a condensation polymer of ethylene glycol and which acid? [S.S.C. Online Graduate Level (T-I) 27.08.2016]

(a) Benzoic Acid
(b) Salicylic Acid
(c) Phthalic Acid
(d) Terephthalic Acid

Correct Answer: (d) Terephthalic Acid

Solution:Terephthalic Acid - Terylene, also known as Dacron, is a polyester formed by the condensation polymerization reaction between ethylene glycol and terephthalic acid.

19. Glycol is used to manufacture which of the following? [S.S.C. Online Graduate Level (T-I) 8.09.2016]

(a) Nylon
(b) Artificial silk
(c) Terylene
(d) Rubber

Correct Answer: (c) Terylene

Solution:Terylene - Ethylene glycol is one of the two monomers used in the production of Terylene (polyethylene terephthalate). The other monomer is terephthalic acid.

20. ______ fiber is used in making bulletproof vests. [S.S.C. Online CHSL (T-I) 15.01.2017]

(a) Nylon-66
(b) Terylene
(c) Kevlar
(d) Lexan

Correct Answer: (c) Kevlar

Solution: Kevlar - Kevlar is a synthetic aramid fiber known for its exceptional tensile strength and heat resistance. These properties make it ideal for use in bulletproof vests and other high-performance applications. Nylon-66 and Terylene do not offer the same level of impact resistance, and Lexan is a polycarbonate plastic used for impact-resistant windows and lenses.