Vulcanised Rubber

Q.

A natural linear polymer of 2-methyl-1, 3-butadiene becomes hard on treatment with sulphur between 373 to 415 K and $-s-s-$ bonds are formed between chains. Write the structure of the product of this treatment?

Q.

Why Ceramics are very hard?

Q.

Discuss the main purpose of vulcanisation of rubber.

Q. What is the utility of vulcanisation of rubber? How is vulcanisation carried out?

Q. Which among the following elements is used in the vulcanization of Rubber?

1. Ni
2. S
3. Na
4. P

Q. Which material is used for vulcanisation of rubber?

1. Iron
2. Sulphur
3. Chlorine
4. Calcium Carbonate

Q. Sulphur is used in the vulcanization of rubber.

1. True
2. False

Q.

To have practicle applications why are cross links quetioined in rubber?

Q. Trans-form of rubber is called ___.

1. Isoprene
2. Neoprene
3. Gutta percha
4. Glyptal

Q. Write names and chemical formulae of monomers used in preparing Buna-S.

Q. Which of the following is used in making automobile tyres and foot wear?

1. Vulcanised rubber
2. Plexi glass
3. Neoprene
4. Glyptal

Q. What is vulcanization of rubber?

Q. Heating rubber with sulphur is known as:

1. galvanization
2. bessemerisation
3. vulcanization
4. sulphonation

Q.

Which of the following has cross-links?

1. Low density polythene
2. Both (a) and (b) are correct
3. Vulcanised rubber
4. Melamine

Q. Heating of rubber with sulphur is called

1. Vulcanisation
2. Sulphonation
3. Galvanisation
4. Bessemerisation

Q. Which of the following type of forces are present in vulcanized rubber?

1. Weakest intermolecular forces
2. Metallic bonding
3. Hydrogen bonding
4. Three dimensional network of bonds

Q. Illustrate the following terms :

Q. What percentage of sulphur is used in the vulcanization of rubber?

1. $5$%
2. $3$%
3. $30$%
4. $55$%

Q. Explain that vulcanised rubber is an elastomer.

Q. Explain the purpose of vulcanization of rubber.

Q. In vulcanization of rubber :

1. sulphur reacts to form a new compound
2. sulphur cross-links are introduced
3. sulphur forms a very thin protective layer over rubber
4. all statements are correct

Q. The tensile strength, elasticity and resistance to abrasion can be increased by a process called ___

1. Galvanisation
2. Vulcanization
3. Bessemerisation
4. Sulphonation

Q. The process of vulcanization was introduced by ____

1. Charles Goodyear
2. Kolbe
3. Wohler
4. Zeigher

Q. Natural rubber is heated with an element X to make it hard, strong and more elastic. X is:

1. zinc
2. lead
3. sulphur
4. $H_2$

Q. In the vulcanization of rubber:

1. sulphur reacts to form a new compound
2. sulphur cross-links are introduced
3. sulphur forms a very thin protective layer over rubber
4. All of the above

Q. (i) What is the role of sulphur in the vulcanisation of rubber?
(ii) Identify the monomers in the given polymer.
(iii) Arrange the following polymers in the decreasing order of their intermolecular forces: Terylene, Polythene, Neoprene.

Q. In a given polymers which is a condensation polymer?

1. Neoprene
2. Buna-S
3. Nylon-6, 6
4. Teflon

Q. The process of vulcanisation makes rubber

1. Soluble in water
2. Less Elastic
3. Soft
4. Hard