Applied Chemistry Multiple Choice Questions on “Mechanism of Polymerization – 1”.
1. Mechanism of polymerisation is classified into _______ types.
a) Two
b) Three
c) Four
d) Five
Answer: a
Clarification: Mechanism of polymerisation is classified into two types. They are chain or addition polymerisation and the step or condensation polymerisation.
2. The functionality of the monomer is a __________ bond.
a) Single
b) Double
c) Triple
d) No
Answer: b
Clarification: The functionality of the monomer is a double bond and bi functional. The chain polymerisation yields the product which is exact multiple of the monomers.
3. The polymerisation takes place by __________ of the monomer molecules.
a) Addition
b) Self addition
c) Dissociation
d) Condensation
Answer: b
Clarification: The polymerisation takes place by self addition of the monomer molecules to each other through the chain polymerisation.
4. The bi products like water, methyl alcohol are produced in chain reaction.
a) True
b) False
Answer: b
Clarification: The bi products like water, methyl alcohol are not produced in the chain reaction. The polymer has the same chemical composition as that of the monomer in chain polymerisation.
5. In how many steps the mechanism of the chain polymerisation is carried out?
a) Two
b) Three
c) Four
d) Five
Answer: b
Clarification: The mechanism of the chain polymerisation is carried out in three steps. They are 1. initiation, 2. propagation and 3. termination.
6. The chain polymerisation mechanism is _______
a) Slow
b) Very slow
c) Rapid
d) Moderate
Answer: c
Clarification: The chain polymerisation mechanism is rapid. An initiator is required to start the polymerisation reaction.
7. The conversion of pi-bond to sigma bond during the chain propagation releases the energy of _________ K.cal/mole.
a) 10
b) 30
c) 40
d) 20
Answer: d
Clarification: The conversion of the pi-bond into the sigma bond during the chain polymerisation releases the energy of the 20K.cal/mole. An initiator is needed to start the polymerisation reaction.
8. Which of the following do not undergo the chain polymerisation?
a) Polyester
b) Vinyl
c) Allyl
d) Dienes
Answer: a
Clarification: The polyester do not undergo the chain polymerisation. The compounds having the double bond undergo chain polymerisation. Olefins, vinyl, allyl and dienes undergo chain polymerisation.
9. Addition polymerisation can be carried out in _________ mechanisms.
a) Two
b) Three
c) Four
d) Five
Answer: b
Clarification: Addition polymerisation can be carried out in three mechanisms. They are: 1 – free radical mechanism, 2 – ionic mechanism, 3 – co-ordination mechanism.
10. Initiators are __________ compounds.
a) Stable
b) Unstable
c) Partially stable
d) Highly stable
Answer: b
Clarification: Initiators are the unstable compounds. For getting stability, they undergo homolytic fusion to produce free radicals.
11. For free radical chain polymerisation _________ are the good initiators.
a) Benzoyl peroxide
b) Hydrogen peroxide
c) Benzoyl peroxide and hydrogen peroxide
d) Neither benzoyl peroxide nor hydrogen peroxide
Answer: c
Clarification: For free radical chain polymerisation, Benzoyl peroxide and hydrogen peroxide are the good initiators. They produce monomer free radicals.
12. The ionic mechanism again divided into _____________
a) Two
b) Three
c) Four
d) Five
Answer: a
Clarification: The ionic mechanism is again dividing into two types. They are: cationic chain polymerisation and anionic chain polymerisation.
13. The __________ of the inhibitor result in the cationic chain polymerisation.
a) Homolytic fusion
b) Partially homolytic fusion
c) Heterolytic fusion
d) Partially heterolytic fusion
Answer: c
Clarification: The heterolytic fusion of the initiator results in the cationic chain polymerisation and homolytic fusion results in a free radical polymerisation.
14. The anion is produced by the __________ initiates the anionic chain polymerisation.
a) Homolytic fusion of initiator
b) Heterolytic fusion of initiator
c) Organo-alkali compounds
d) Inorganic compounds
Answer: c
Clarification: The anion is produced by the organo-alkali compounds like ethyl sodium, methyl potassium, butyl lithium etc initiates the anionic chain polymerisation.
15. The catalyst used in the co-ordination polymerisation is __________
a) Ziegler-natta catalyst
b) Vanadium pent-oxide
c) Nitric oxide
d) Zeonar
Answer: a
Clarification: The catalyst used in the co-ordination polymerisation is Ziegler-natta catalyst. Combination of the metal halides and organometallic compounds are called as Ziegler-natta catalyst.