MCQ - Synthetic Fibers And Plastics - Notes | Study Science Class 8 - Class 8

Q1. Fibre obtained by chemical treatment of wood pulp is called ___________.
(a) Natural silk
(b) Rayon
(c) Nylon
(d) Polyester

Correct Answer is Option (b)

• Natural Silk: The protein fibre of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons.
• Rayon: Rayon is a manufactured regenerated cellulose fibre. It is made from purified cellulose, primarily from wood pulp, which is chemically converted into a soluble compound.
• Nylon: Nylon is a strong, light synthetic fibre. Nylon thread is made from the polymerization of an amine and an acid chloride.
• Polyester: Polyester is a synthetic polymer made of purified terephthalic acid or its dimethyl ester dimethyl terephthalate and mono ethylene glycol.

Rayon Fabric

Correct Answer is Option (c)

• Nylon was first commercially synthesized fibre. 
• The production of nylon was started almost simultaneously in New York and London, thus it got its name (NY for New York and Lon for London) as nylon. 
• Nylon is synthesized from coal, water and air. Fibre of nylon is very strong and it also resembles silk.

Correct Answer is Option (d)

• Steel is an alloy.
• Nylon is a polymer (synthetic fibre). It is a polyamide. The amide linkage between the monomers makes nylon fibres very strong.
• Hence, Nylon wire is stronger than steel wire.

Correct Answer is Option (c)

• PET (polyethylene terephthalate) is a very familiar form of polyester. 
• It is used for making bottles, utensils, films, wires and many other useful products.

Correct Answer is Option (d)

• Polyester is a man-made or synthetic fibre made up of repeating units of a chemical substance called esters. 
• Esters are sweet smelling compounds, which are primarily made of carbon, hydrogen, and oxygen.

Correct Answer is Option (a)

• Acrylic is known as artificial wool or synthetic wool because it resembles wool. 
• Acrylic is cheaper than natural wool and can be dyed in various colour. 
• This makes acrylic is very popular among other fabrics.

Correct Answer is Option (c)

• They melt on heating and stick to our body when catching fire and causes more harm. 
• We must prefer cotton clothes while working with fire because it does not melt and keep us safe.  
• Cotton fibres are soft and comfortable. It has good absorbency and it soaks oil splatter. It does not melt on heating and thus causes less harm.

Correct Answer is Option (d)
Synthetic fibres are synthesised from raw material called petrochemicals.

Correct Answer is Option (c)
Nylon fibres are very strong so they are used for making parachutes and ropes for rock-climbing.

Correct Answer is Option (d)

• Terylene is a popular trademark of synthetic polyester fibre.
• The fabric is based on terephthalic acid, characterized by lightness and crease resistance and used for clothing, sheets, ropes, sails, etc.