Class 12th

This is a multiple choice answer as classified in NCERT Exemplar

(c) Birth control pills contain a mixture of estrogen and progesterone derivatives. Both of these are sex hormones. Progesterone suppresses ovulation and estrogen control the menstrual cycle.

This is a multiple choice answer as classified in NCERT Exemplar

(d) Antiseptics are applied to the living tissues such as wounds, cuts and diseased skin surfaces. Antiseptic medicines such as antibiotics cannot be ingested.

This is a assertion and reason answer type question as classified in NCERT Exemplar

(iv) Assertion is correct statement and reason is wrong statement. (v) Assertion is wrong statement and reason is correct statement.

Explanation:  Most of the Synthetic polymers are not biodegradable. A large number of the polymers are resistant to the degradation process of the environment and therefore, are responsible for the accumlation of polymeric solid waste material.

This is a assertion and reason answer type question as classified in NCERT Exemplar

(i) Assertion and reason both are correct statements but reason does not explain assertion.

Explanation: Thermosetting polymers are cross linked polymers. They are highly branched polymers with high molecular masses. These polymers on heating undergo cross linking in moulds. They become infusible on heating.

This is a assertion and reason answer type question as classified in NCERT Exemplar

(v) Assertion is wrong statement and reason is correct statement.

Explanation: Synthetic rubber is a type of rubber polymer that are capable of getting stretched to twice of its length. They are homopolymers of either 1,3-butadiene derivatives or copolymers of butadiene. Polychloroprene or neoprene is a type of synthetic rubber.

This is a assertion and reason answer type question as classified in NCERT Exemplar

(ii) Assertion and reason both are correct statements and reason explains the assertion.

Explanation: Polyamides are best used as fibres because of high tensile strength. They have the strongest intermolecular forces of attraction like hydrogen bonding. It lead to close packing of chains and increase the crystalline character.

This is a assertion and reason answer type question as classified in NCERT Exemplar

(i) Assertion and reason both are correct statement but reason does not explain assertion.

Explanation: Olefinic monomers undergo addition polymerisation. The molecules of the same monomer or different monomer are added together to form this type of polymer. This mode of polymerisation leads to an increase in chain length.

This is a assertion and reason answer type question as classified in NCERT Exemplar

(iv) Assertion is correct statement and reason is wrong statement. (v) Assertion is wrong statement and reason is correct statement.

Explanation:  Most of the Synthetic polymers are not biodegradable. A large number of the polymers are resistant to the degradation process of the environment and therefore, are responsible for the accumlation of polymeric solid waste material.

This is a assertion and reason answer type question as classified in NCERT Exemplar

(ii) Assertion and reason both are correct statements and reason explains the assertion.

Explanation:  Rayon is a semi synthetic polymer. It is preferred over cotton fabric because its properties are improved by acetylation.