Solution of Chapter 3. Synthetic Fibers and Plastics (Lakhmir Singh & Manjit Kaur - Science Book)

Name the units of which cellulose polymer is made.

Name the man-made fibre prepared from natural materials.

Name the man-made fibre which is regarded as artificial silk.

Name the fibre obtained by the chemical treatment of wood pulp (or cellulose).

Name the first fully synthetic fibre.

Name the fibre used for making parachutes and rock climbing ropes.

Which synthetic fibre contains the organic group similar-to those which give fruits their sweet smell.

Which synthetic fibre feels like wool and used as a substitute for wool?

To which kind of synthetic fibres does terylene belong?

State one disadvantage of using synthetic fibres for making clothes.

Name the form of polyester which is replacing materials like glass and used for making bottles and jars.

Name four different plastics.

Give one use of Teflon.

Which of the two is a thermosetting plastic: PVC or bakelite?

Fill in the following blanks with suitable words:

(a) Synthetic fibres are also called..........or……fibres.

(b) Synthetic fibres are made from raw materials called.............

(c) Like synthetic fibres, plastic is also a ............

(d) The use of plastics can be reduced by using bags made of ............or ................instead of polythene bags.

What is a polymer? Name the natural polymer from which cotton is made.

State the characteristics of synthetic fibres.

What is nylon? State the important properties of nylon.

Give the important uses of nylon.

What is polyester? Name a popular polyester.

Arrange the following fibres in the order of increasing strength (keeping the fibre of least strength first): Nylon, Cotton, Wool, Polyester, Silk

What is PET? State the uses of PET.

What is acrylic? State one important property of acrylic.

Write the uses of acrylic fibres.

Why should we not wear clothes made of synthetic fibres (like nylon or polyester) while working in the kitchen?

What type of shirts should we buy for summer: cotton shirts or shirts made from synthetic materials (like polyester)? Give reason for your answer.

Explain how, manufacturing of synthetic fibres is actually helping in the conservation of forests.

What are plastics? Name any five commonly used articles made of plastics.

What are the various types of plastics? Give two examples of each type of plastics.

Why are thermoplastics not used for making frying pan handles?

Explain why, frying pan handles are made of thermosetting plastics.

Why are electric witches, plugs and sockets made of thermosetting plastics?

Explain the difference between thermoplastics and thermosetting plastics.

Should the handle and bristles of a toothbrush be made of the same type of plastic material? Explain your answer.

Explain why, plastic containers are preferred for storing food.

Choose the thermoplastics and thermosetting plastics from the following: Melamine, Polythene, Bakelite, Polyvinyl chloride

State two uses of polythene.

Write the full form of PVC. Is it thermoplastic or thermosetting plastic?

Write two uses of Bakelite.

State two uses of melamine.

Give two uses of PVC.

Write some of the uses of plastics in healthcare industry.

Classify the following as biodegradable and non-biodegradable materials: Woollen clothes, Polythene bags, Paper, Aluminium cans, Toothbrush, Peels of vegetables and fruits, Cotton cloth, Jute bag, Electric switch, Frying pan handle.

State whether plastic is biodegradable or non-biodegradable? Give reasons for your answer.

Explain how, the use of plastics has a bad effect on the environment.

Explain why, the disposal of plastic wastes is a major problem. Give two reasons only.

What are the various ways to save the environment from excessive plastic wastes?

How do carelessly thrown plastic bags (polythene bags) affect:

(a) dirty water drains and sewers?

(b) animals (such as cows)?

What is meant by the 3R's principle in the context of use of plastics?

State the various ways in which we can avoid (or minimize) the use of plastics.

What is rayon? How is rayon made?

Give any two uses of rayon.

What are synthetic fibres? Name any two synthetic fibres.

Why have synthetic fibres become more popular than natural fibres?

What are thermoplastics? Give two examples of thermoplastics.

What are thermosetting plastics? Give two examples of thermosetting plastics.

Explain why, thermoplastics become soft on heating but thermosetting plastics do not become soft on heating. Draw labelled diagrams to illustrate your answer.

What is meant by biodegradable and non-biodegradable materials? Give examples of two biodegradable and two non-biodegradable materials.

Rayon is different from truly synthetic fibres because:

The synthetic material which can be used for marking fabrics as well as shatterproof bottles and jars is:

Which of the following has cross-linked polymer chains?

The man-made fibre made from the cellulose polymer is:

Which of the following is not a thermoplastic polymer?

The synthetic polymer which can be used as a substitute for wool for making sweaters and shawls, etc. is:

Which of the following is not a synthetic fibre?

The synthetic fibre which contains the group similar to those which give fruits their ‘sweet smell’ is:

The man-made fibre which contains identical to:

One of the following man-made fibre is not prepared from raw materials obtained from petrochemicals. This one is:

Which of the following plastics do not have cross-links between their polymer chains

(A) Nylon

(B) Nekamine

(C) Terylene

(D) Bakelite

The clothes of a person working in the kitchen catch fire accidently causing severe burns. The person is most likely wearing clothes made of:

The plastic which is coated on the uniforms of firemen to make them fire-resistant is:

Which of the following is a man-made fibre prepared from wood-pulp?

The manufacture of one of the following artificial fibres contributes to deforestation this fibre is :

The non-stick coating on frying pans is that of a plastic called:

Which of the following plastics is used for making electric switches?

Which of the following are thermosetting polymers?

(A) Melamine

(B) Terylene

(C) Polythene

(D) Bakelite

The similarity between artificial silk and cotton is that:

Which of the following plastic objects can be recycled?

(A) Electric socket

(B) Polythene bag

(C) PVC pipe

(D) Ashtray

Match the terms of column A correctly with the phrases given in column B:

Column A

(i) Polyester

(ii) Teflon

(iii) Rayon

(iv) Nylon

Column B

(a) Prepared by using wood pulp

(b) Used for making parachutes

(c) Used to make non- stick cookware

(d) Fabrics do not wrinkle easily

Which plastic is used:

(a) for making uniforms of fire-men fire resistant?

(b) for giving non-stick coating on frying pans?

(c) for making handles of frying pans?

(d) for making insulation of electric wires?

(e) for making electric switches?

(f) for making flexible water bottles?

Which of the following articles made of plastics ‘can be recycled’ and which cannot be recycled’ ? give reasons for your choice?

Telephone instruments, plastic toys, cooker handles, plastic covering on electrical wires, electric switches, ballpoint pens, carry bags, plastic bottles, plastic chairs

Out of the following materials:

cotton, nylon, terylene, wool, Pet, acrylic

(a) which materials are polyesters?

(b) which materials is a polyamide?

(c) which material is used as a substitute for wool?

(d) which material is used as a substitute for glass?

The synthetic fibre A is chemically a polyamide whereas the synthetic fibre B contains a large number of ester groups. another synthetic fibre C is made of a polymer D which consists of a number of glucose units joined one after the other.

(a) Which fibre could be (i) terylene (ii) rayon and nylon?

(b) Name the polymer D.

(c) Which fibre (A, B or C) is prepared from a natural raw material?

(d) Which fibre (A, B or C) contains the same type of groups as those in a PET jar?