Tag: chemistry

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Multiple choice chemistry polymer synthetic rubber rubber manmade materials

Vulcanization of rubber helps to make rubber hard and resistant to hot and cold conditions.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vulcanization is a process in which the strength, stability, and elasticity of rubber are increased by subjecting it to heat, in the presence of sulphur. As a result, cross-linking occurs between the chains of rubber molecules and sulphur atoms.

Multiple choice chemistry manmade materials synthetic rubber rubber polymer

The process involving heating of rubber with sulphur is called ___

  1. Galvanisation

  2. Vulcanization

  3. Bessemerisation

  4. Sulphonation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Vulcanisation of Rubber - Natural rubber  becomes soft at high temperature (>$335$ K) and brittle at low temperature (<$283$ K) and shows high water absorption capacity.
The process of  vulcanisation includes heating of raw rubber with sulphur and an appropriate additive at temperature range between $373$ K  to $415$ K. Sulphur foms crosslinks at reactive sites of double bonds and thus, rubber gets stiffened.

Multiple choice chemistry manmade materials synthetic rubber rubber polymer

The synthetic polymer which resembles natural rubber is:

  1. Neoprene

  2. Buna-S

  3. Nylon

  4. Rayon
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Neoprene resembles natural rubber. 


Natural rubber is a linear polymer of $2$-methyl-$1,:3$-butadiene called as isoprene and Neoprene is a linear polymer of $2$-chloro-$1,:3$-butadiene called as chloroprene.

Option A is correct.

Multiple choice chemistry manmade materials synthetic rubber rubber polymer

Chloroprene is used in making

  1. synthetic rubber

  2. plastic

  3. petrol

  4. All of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Chloroprene is the monomer of neoprene, a synthetic rubber formed by the free radical polymerisation of choloroprene.


$nCH _2-CCl-CH=CH _2 \xrightarrow {Polymerisation} -[CH _2-CCl=CH-CH _2]-$

Multiple choice chemistry manmade materials synthetic rubber rubber polymer

The process of vulcanization was introduced by ____

  1. Charles Goodyear

  2. Kolbe

  3. Wohler

  4. Zeigher
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Charles Goodyear invented vulcanization process in $1839$.
Vulcanisation is a process involving heating of rubber with sulphur is called vulcanisation.

Multiple choice chemistry manmade materials synthetic rubber rubber polymer

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

  1. Galvanisation

  2. Vulcanization

  3. Bessemerisation

  4. Sulphonation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Vulcanization is the process of heating rubber with sulphur to improve its mechanical properties, such as tensile strength, elasticity, and resistance to abrasion.

Multiple choice chemistry manmade materials synthetic rubber rubber polymer

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

  1. Vulcanised rubber

  2. Neoprene

  3. Plexi glass

  4. Glyptal
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vulcanised rubber is used in making automobile tyres and foot wear. Heating of rubber with sulphur is called as vulcanisation. It makes the rubber hard and more flexible.

Multiple choice chemistry manmade materials synthetic rubber rubber polymer

Vulcanization of rubber helps to make rubber hard and resistant to hot and cold conditions.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Vulcanization of rubber is a chemical process used for converting natural rubber into more durable material by addition of sulphur.
Vulcanization of rubber helps to make rubber hard and resistant to hot and cold conditions. 

Multiple choice chemistry manmade materials synthetic rubber rubber polymer

Which of the following has cross-linked polymer?

  1. Vulcanised rubber

  2. Nylon

  3. Phenol-formaldehyde resins
  4. Both $A$ and $C$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Vulcanised rubber contains sulphur bridges between polymer chains, and phenol-formaldehyde resins (like Bakelite) are thermosetting polymers with a highly cross-linked structure. Both are examples of cross-linked polymers.