Here are the Assertion and Reasoning questions for Chapter 15: Polymers for CBSE Class 12 Chemistry:
1. Assertion: Addition polymerization involves the breaking of
a double bond in a monomer.
Reason: In addition polymerization, the monomers join without
the loss of any molecule.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Addition polymerization involves the breaking of a
double bond in the monomer to form a long chain polymer. The process does not
involve the loss of any atoms or molecules.
2. Assertion: Polymers formed through condensation
polymerization require two different types of functional groups.
Reason: In condensation polymerization, two molecules react to
eliminate a small molecule like water or alcohol.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: In condensation polymerization, two different
types of functional groups react, eliminating a small molecule such as water,
alcohol, or HCl.
3. Assertion: Low-density polyethylene (LDPE) is used for
making squeeze bottles and plastic bags.
Reason: LDPE has a highly branched structure that results in a
flexible material.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: LDPE has a branched structure that makes it
flexible and suitable for items like squeeze bottles and plastic bags.
4. Assertion: Bakelite is a thermosetting plastic.
Reason: Thermosetting plastics do not soften on heating because
they have a three-dimensional network of bonds.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Bakelite is a thermosetting plastic, which forms a
rigid, three-dimensional network structure that does not soften on heating.
5. Assertion: The polymerization of ethene to form polyethylene
is an example of addition polymerization.
Reason: Addition polymerization involves the opening of a
double bond in the monomer and the formation of a long polymer chain.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: In the polymerization of ethene to polyethylene,
the double bond in ethene opens, and the monomers add to form a polymer chain.
6. Assertion: Nylon-6,6 is a condensation polymer.
Reason: Nylon-6,6 is formed by the reaction of hexamethylene
diamine and adipic acid with the elimination of water molecules.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Nylon-6,6 is made through condensation
polymerization between hexamethylene diamine and adipic acid, releasing water
molecules.
7. Assertion: Polypropylene is used for making ropes and
carpets.
Reason: Polypropylene is a thermoplastic polymer that is
resistant to wear and tear.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Polypropylene is a thermoplastic polymer with high
wear resistance, making it suitable for products like ropes and carpets.
8. Assertion: Polystyrene is used for making disposable
cutlery.
Reason: Polystyrene is rigid and brittle, which makes it
suitable for products like cutlery.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Polystyrene is rigid and brittle, making it
suitable for manufacturing items like disposable cutlery.
9. Assertion: Bakelite and melamine are examples of
thermosetting plastics.
Reason: Thermosetting plastics can be softened and reshaped
when heated.
Answer: (D) Assertion is true, but reason is false.
Explanation: Bakelite and melamine are thermosetting plastics,
which once set, cannot be reshaped or softened on heating, contrary to the
assertion.
10. Assertion: Addition polymers are formed by the addition of
monomers that have a double bond.
Reason: Addition polymerization results in the loss of a small
molecule like water or alcohol.
Answer: (C) Assertion is true, but reason is false.
Explanation: Addition polymerization does not involve the loss
of any molecule. It only requires the addition of monomers with double bonds.
11. Assertion: Teflon (PTFE) is used as a non-stick coating for
cookware.
Reason: Teflon is a polymer of tetrafluoroethylene, which has a
high resistance to heat and chemical corrosion.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Teflon is a polymer of tetrafluoroethylene with
high heat and chemical resistance, making it ideal for non-stick cookware.
12. Assertion: Polymers can be classified into two categories:
addition polymers and condensation polymers.
Reason: Addition polymers are formed when monomers with
functional groups react, while condensation polymers are formed by the
combination of monomers with elimination of a small molecule.
Answer: (C) Assertion is true, but reason is false.
Explanation: The distinction is incorrect. In addition
polymerization, monomers with double bonds react, and in condensation
polymerization, monomers with functional groups eliminate small molecules.
13. Assertion: Nylon-6 is a polymer formed from a single
monomer.
Reason: Nylon-6 is made by the polymerization of caprolactam.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Nylon-6 is made through the ring-opening
polymerization of caprolactam, which is a single monomer.
14. Assertion: The polymerization of 1,3-butadiene results in
the formation of synthetic rubber.
Reason: 1,3-butadiene is a conjugated diene and undergoes
addition polymerization to form synthetic rubber.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: 1,3-butadiene undergoes addition polymerization to
form synthetic rubber, a material widely used for tires and various industrial
applications.
15. Assertion: Polymers like polyethylene and polypropylene are
examples of addition polymers.
Reason: Addition polymers are formed by the polymerization of
monomers containing a double bond.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Polyethylene and polypropylene are formed through
addition polymerization, where the monomers contain double bonds.
16. Assertion: Thermoplastic polymers can be reshaped upon
heating.
Reason: Thermoplastics have linear or branched structures,
allowing them to be re-melted and reshaped.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Thermoplastics have a flexible structure that
allows them to be melted and re-shaped when heated.
17. Assertion: Addition polymers cannot be degraded easily.
Reason: Addition polymers have long, strong covalent bonds,
making them resistant to degradation.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Addition polymers, due to their strong covalent
bonds, are resistant to chemical degradation, making them difficult to break
down.
18. Assertion: Condensation polymers are usually more rigid
than addition polymers.
Reason: Condensation polymers involve the elimination of small
molecules, which leads to the formation of stronger covalent bonds and more
rigid structures.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: The cross-linking in condensation polymers and the
loss of small molecules during polymerization lead to stronger and more rigid
structures.
19. Assertion: Polyvinyl chloride (PVC) is used for making
pipes and flooring.
Reason: PVC is rigid and can withstand high pressures and wear,
making it suitable for pipes and flooring.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: PVC is a rigid polymer with high resistance to
wear and tear, making it ideal for use in pipes and flooring materials.
20. Assertion: Polyamide is a type of polymer that forms amide
linkages between monomers.
Reason: Polyamides are condensation polymers formed by reacting
diamines with dicarboxylic acids.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Polyamides, like nylon, are formed by the
condensation reaction between diamines and dicarboxylic acids, resulting in
amide linkages.
21. Assertion: Nylon-6,6 is a stronger polymer than nylon-6.
Reason: Nylon-6,6 has a higher molecular weight due to its two
different monomers, making it more crystalline and stronger.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Nylon-6,6 has two different monomers, making it
more crystalline and thus stronger than nylon-6, which is made from a single
monomer.
22. Assertion: Polymers with branched structures tend to have
lower density than polymers with linear structures.
Reason: Branched polymers cannot pack closely together, which
increases their volume and decreases their density.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Branched polymers have irregular shapes that
prevent them from packing tightly together, leading to lower density compared to
linear polymers.
23. Assertion: Polyethylene is used for making plastic bags and
bottles.
Reason: Polyethylene is a versatile thermoplastic with
low-density and high flexibility.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Polyethylene, especially low-density polyethylene
(LDPE), is flexible and commonly used for making plastic bags and bottles.
24. Assertion: Cross-linked polymers are harder and more rigid
than linear polymers.
Reason: Cross-linked polymers have covalent bonds between their
chains, which prevent them from sliding past each other.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Cross-linked polymers have a network structure due
to covalent bonds between chains, making them more rigid compared to linear
polymers.
25. Assertion: Thermosetting polymers cannot be remolded after
the initial molding.
Reason: Thermosetting polymers form a three-dimensional network
of bonds that cannot be re-broken once formed.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Thermosetting polymers have a strong,
three-dimensional network structure that cannot be remolded after being set.
26. Assertion: The monomer for making polystyrene is styrene.
Reason: Styrene is an alkene that undergoes addition
polymerization to form polystyrene.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Polystyrene is formed by the addition
polymerization of styrene, a monomer with a double bond.
27. Assertion: Plasticizers are added to polymers to increase
their flexibility.
Reason: Plasticizers decrease the intermolecular forces between
polymer chains, making the material more flexible.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Plasticizers reduce the intermolecular forces
between polymer chains, allowing the chains to move more freely and making the
polymer more flexible.
28. Assertion: Polyvinyl acetate (PVA) is used for making
adhesives and paints.
Reason: PVA is soluble in water and forms a sticky, adhesive
layer when dry.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Polyvinyl acetate is a water-soluble polymer
commonly used in adhesives and paints due to its sticky, film-forming
properties.
29. Assertion: Polymers like Teflon and PVC are used in the
electrical industry.
Reason: These polymers have excellent insulating properties and
are resistant to heat and chemicals.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Teflon and PVC are excellent insulators and
resistant to heat and chemicals, making them ideal for use in electrical
applications.
30. Assertion: Bakelite is used for making electrical
insulators.
Reason: Bakelite is a highly heat-resistant and rigid
thermosetting plastic, making it suitable for electrical insulation.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Bakelite is a thermosetting plastic with high heat
resistance and rigidity, making it ideal for use in electrical insulators.
31. Assertion: The polymerization of butadiene with styrene
forms a copolymer known as SBR (styrene-butadiene rubber).
Reason: SBR is a synthetic rubber with high elasticity,
commonly used in automobile tires.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: SBR is formed by the polymerization of butadiene
and styrene, and its high elasticity makes it ideal for use in automobile tires.
32. Assertion: Addition polymers typically have lower molecular
weights compared to condensation polymers.
Reason: Addition polymerization involves the addition of
monomers without the elimination of any molecules, leading to shorter chains.
Answer: (C) Assertion is true, but reason is false.
Explanation: Addition polymers usually have high molecular
weights, as they are formed by the addition of monomers without losing any
molecules. Condensation polymers often have lower molecular weights due to the
loss of small molecules during polymerization.
33. Assertion: Polymers can be classified into natural and
synthetic types.
Reason: Natural polymers, like cellulose and proteins, are
obtained from living organisms, while synthetic polymers are made through
chemical reactions.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Natural polymers are derived from living
organisms, while synthetic polymers are chemically synthesized.
34. Assertion: Polycarbonate is a high-strength polymer used in
bulletproof windows.
Reason: Polycarbonate has a rigid structure with high impact
resistance, making it suitable for applications like bulletproof windows.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Polycarbonate is known for its strength and high
impact resistance, making it ideal for applications requiring durability, such
as bulletproof windows.
35. Assertion: The addition of a plasticizer makes PVC softer
and more flexible.
Reason: Plasticizers reduce the intermolecular forces between
polymer chains, allowing them to slide past each other.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Plasticizers reduce the rigidity of the polymer by
weakening the intermolecular forces between the chains, making the material
softer and more flexible.
36. Assertion: The polymerization of ethylene glycol and
terephthalic acid results in the formation of polyester.
Reason: Polyesters are condensation polymers that form ester
linkages between monomers.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: The reaction between ethylene glycol and
terephthalic acid results in the formation of polyester through condensation
polymerization, where ester linkages are formed.
37. Assertion: Addition polymers like polyethylene and
polystyrene have no functional groups.
Reason: Addition polymers are made by adding monomers with
double bonds without any loss of atoms, so they do not require functional
groups.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Addition polymers are made from monomers with
double bonds and do not require functional groups because they undergo addition
without losing any atoms.
38. Assertion: A polymer formed by the reaction of an amine
group and a carboxyl group is known as a polyamide.
Reason: Polyamides are condensation polymers where amide
linkages are formed by the elimination of water.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Polyamides are formed by the condensation reaction
between an amine group and a carboxyl group, with the elimination of water
molecules, forming amide linkages.
39. Assertion: Bakelite is used for making electrical switches.
Reason: Bakelite is a poor conductor of electricity, making it
ideal for electrical applications.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Bakelite, being a poor conductor of electricity,
is ideal for making electrical switches, where electrical insulation is
essential.
40. Assertion: The use of nylon fibers in parachutes is due to
their high strength.
Reason: Nylon is a strong, durable polymer with excellent
tensile strength.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Nylon's high tensile strength and durability make
it ideal for use in applications like parachutes, where strength is critical.
41. Assertion: Thermoplastic polymers can be remolded when
heated.
Reason: Thermoplastic polymers do not undergo cross-linking, so
they can be softened and reshaped when heated.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Thermoplastic polymers can be reheated and
remolded because they do not undergo cross-linking, allowing them to soften and
regain their shape.
42. Assertion: Synthetic rubbers are often preferred over
natural rubbers for industrial use.
Reason: Synthetic rubbers can be tailored for specific
properties like improved durability and resistance to wear.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Synthetic rubbers are preferred because they can
be engineered for specific properties, such as increased durability, wear
resistance, and better performance in various conditions.
43. Assertion: Polymers with high molecular weight have high
melting points.
Reason: High molecular weight polymers have stronger
intermolecular forces, requiring more energy to break the bonds and melt the
polymer.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: High molecular weight polymers have stronger
intermolecular forces, leading to higher melting points compared to polymers
with lower molecular weight.
44. Assertion: Rubber bands lose their elasticity over time.
Reason: Rubber undergoes a process called aging, where the
polymer chains break down and lose their ability to return to the original
shape.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Over time, the polymer chains in rubber break down
due to aging, leading to a loss of elasticity in rubber bands.
45. Assertion: Plastics like PVC are used in plumbing pipes
because they are resistant to corrosion.
Reason: PVC is chemically resistant and does not corrode easily
when exposed to water and chemicals.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: PVC is resistant to corrosion and does not degrade
when exposed to water and chemicals, making it ideal for use in plumbing.
46. Assertion: Natural rubber is a polymer made from the
monomer isoprene.
Reason: Isoprene undergoes polymerization to form natural
rubber with high elasticity.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Natural rubber is indeed made from the monomer
isoprene, and its polymerization results in a polymer with high elasticity.
47. Assertion: Teflon is used as a non-stick coating for
cooking utensils.
Reason: Teflon has a very low coefficient of friction, which
prevents food from sticking to its surface.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Teflon's low coefficient of friction makes it
ideal for use as a non-stick coating on cooking utensils.
48. Assertion: Polymers can be biodegradable or
non-biodegradable.
Reason: Biodegradable polymers can be broken down by
microorganisms, while non-biodegradable polymers persist in the environment.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Biodegradable polymers decompose with the help of
microorganisms, while non-biodegradable polymers remain in the environment for a
long time.
49. Assertion: Conducting polymers are used in electronic
devices.
Reason: Conducting polymers have electrical conductivity,
making them suitable for use in electronic components.
Answer: (A) Assertion is true, reason is true, and reason is
the correct explanation for assertion.
Explanation: Conducting polymers, due to their ability to
conduct electricity, are used in various electronic devices such as sensors and
displays.