Tag: chemistry

Questions Related to chemistry

Polythene is a polymer. The monomer of this is:

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Propene

  2. Isoprene

  3. Chloroprene

  4. Ethene

Show answer
Correct Option: D
Explanation:

Polythene is a polymer made from the monomer-ethene.

$nH _2C=CH _2 \xrightarrow {polymerization} -[H _2C-CH _2]- _n$
  (ethene)                                                 (polythene)

Fishing nets are made of

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. rayon

  2. dacron

  3. nylon

  4. viscose rayon

Show answer
Correct Option: C
Explanation:

Nylon is strong enough to bear heavy weights, extend and then regain its original shape and length, making it very resourceful in fishing nets and also durable.

The polymer formed by condensation of adipic acid and hexamethylene diamine is:

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Isoprene

  2. Rayon

  3. Terylene

  4. Nylon-$6, 6$

Show answer
Correct Option: D

Hair sprays generally contain resins in a volatile solvent. Upon drying, they leave a thin film that holds the hair in place. Which of the following is a resin used in hair spray?

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Polyester

  2. Polyvinyl alcohol

  3. Polyvinyl pyrrolidone (PVP)

  4. Polythene

Show answer
Correct Option: C
Explanation:
$PVP$ (Polyvinyl pyrrolidone) is a versatile ingredient which is used in cosmetics and beauty industry as a bindes, film former, emulsion stabilizer, suspending agent and hair fixative used in products like mascara, eyeliner, hair conditioners, hair sprays and shampoos.

Which of the following polymers can be made by condensation polymerisation reaction?

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Dacron

  2. Nylon - $6,: 6$

  3. Bakelite

  4. Polyethylene

Show answer
Correct Option: A,B,C
Explanation:

Condensation polymers are formed by repeated condensation reactions between two different bi-functional or tri-functional monomeric units. In these polymerisation reactions, the elimination of small molecules such as water, alcohol, hydrogen chloride, etc. takes place. 

Dacron, Nylon-6.6 and Bakelite are produced by condensation polymerisation.

On the other hand, Polyethylene is formed by breakage of the double bond and there is no elimination of molecules.


Which of the following is/are not a condensation copolymer?

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. Nylon-$6$

  2. Nylon-$6,6$

  3. Dacron

  4. PVC

Show answer
Correct Option: A,D
Explanation:
The condensation polymers are formed by repeated condensation reaction between two different bi-functional or tri-functional monomeric units. 

In these polymerisation reactions, the elimination of small molecules such as water, alcohol, hydrogen chloride, etc. take place. The examples are terylene (dacron), nylon 6, 6, etc. For example, nylon 6, 6 is formed by the condensation of hexamethylenediamine with adipic acid.

When two different types of monomers are joined in the same polymer chain, the polymer is called a copolymer. 
Nylon 6 is a condensation polymer but it's not a co-polymer.
PVC is an addition polymer.

Hence, options A and D are correct.

Nylon-$6$ is prepared by linear condensation homopolymerization reaction of: 

types of polymerisation reactions condensation polymerisation polymer polymers chemistry

  1. caprolactum

  2. hexamethylene diamine and adipic acid

  3. $6$-aminohexanoic acid

  4. acrylonitrile

Show answer
Correct Option: A
Explanation:

Solution:- (A) Caprolactam

Nylon-$6$ is prepared by linear condensation homopolymerization reaction of caprolactam.
$n \left( \text{Caprolactum} \right) \xrightarrow[{N} _{2}]{533 \; K} \text{Nylon}-6$

Air is an example of __________.

water and air and their importance natural resources- air, water and land air around us air chemistry

  1. gas solid solution

  2. gas gas solution

  3. solid solid solution

  4. solid gas solution

Show answer
Correct Option: B
Explanation:

Air is a mixture of gases. So, solute and solvent both are gases.

hence, air is known as gas gas solution.

Which is a green house gas?
A) Methane 

B) Chlorofluorocarbons 
C) $CO _{2}$

water and air and their importance natural resources- air, water and land air around us air chemistry introduction to natural resources land

  1. $A$ and $B$

  2. $B$ and $C$

  3. $C$ and $D$

  4. $A, B$ and $C$

Show answer
Correct Option: D
Explanation:

Greenhouse effect
* The progressive heating up of surface of the earth is earth is called green house effect or global warming.
 $CO _2$ and $H _2O$ block a part of the heat (IR) emitted by the earth & reflect back. Due to this earth surface gets heated up.
 50% in $CO _2$ content of air can increase the surface temperature of the earth by $3^oC$.
* In addition to $CO _2$ , the other green - house gases are CFCs (17%), $O _3$ (18%), NO (4%), water vapour (2%).

Which of the following is not a sink for CO?

water and air and their importance natural resources- air, water and land air around us air chemistry introduction to natural resources land

  1. Haemoglobin

  2. Microorganims present in the soil

  3. Oceans

  4. None of the above

Show answer
Correct Option: A
Explanation:


* Incomplete combustion of fossil fuels liberate CO into air. 80% of CO is released from automobiles.


* Permissible level of CO in air is 9 ppm. It reduces $O _2$ supply in human by forming a stable carboxyhaemoglobin.

$2C+O _2\rightarrow 2CO$
$2CH _4+3O _2\rightarrow 2CO+4H _2O$

* CO interacts with oxyhaemoglobin ($O _2Hb$) and forms carboxyhaemoglobin (CO-Hb) as :

$O _2Hb+CO\rightarrow COHb+O _2$

* CO has high affinity for haemoglobin than that of oxygen.

Therefore, option A is correct.