Tag: chemistry

Questions Related to chemistry

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

chemistry polymer synthetic rubber rubber manmade materials

  1. True

  2. False

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Correct Option: A
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.

The process involving heating of rubber with sulphur is called ___

chemistry manmade materials synthetic rubber rubber polymer

  1. Galvanisation

  2. Vulcanization

  3. Bessemerisation

  4. Sulphonation

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Correct Option: B
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.

The synthetic polymer which resembles natural rubber is:

chemistry manmade materials synthetic rubber rubber polymer

  1. Neoprene

  2. Buna-S

  3. Nylon

  4. Rayon

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Correct Option: A
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.

Chloroprene is used in making

chemistry manmade materials synthetic rubber rubber polymer

  1. synthetic rubber

  2. plastic

  3. petrol

  4. All of the above

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Correct Option: A
Explanation:

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


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

The process of vulcanization was introduced by ____

chemistry manmade materials synthetic rubber rubber polymer

  1. Charles Goodyear

  2. Kolbe

  3. Wohler

  4. Zeigher

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Correct Option: A
Explanation:

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

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

chemistry manmade materials synthetic rubber rubber polymer

  1. Galvanisation

  2. Vulcanization

  3. Bessemerisation

  4. Sulphonation

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Correct Option: B

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

chemistry manmade materials synthetic rubber rubber polymer

  1. Vulcanised rubber

  2. Neoprene

  3. Plexi glass

  4. Glyptal

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Correct Option: A
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.

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

chemistry manmade materials synthetic rubber rubber polymer

  1. True

  2. False

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Correct Option: A
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. 

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

chemistry manmade materials synthetic rubber rubber polymer

  1. $5$%

  2. $3$%

  3. $30$%

  4. $55$%

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Correct Option: A
Explanation:

$5$% of sulphar is used in order to extent the stiffness of valcanised rubber.

Which of the following has cross-linked polymer?

chemistry manmade materials synthetic rubber rubber polymer

  1. Vulcanised rubber

  2. Nylon

  3. Phenol-formaldehyde resins

  4. Both $A$ and $C$

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Correct Option: D