Engineering Chemistry I Practice Test 9

1. Polystyrene is prepared by ___________ polymerisation of styrene.

Free radical

Condensation

Anionic

Cationic

2. The polymer in which alternate chiral centres have the same configuration is called ____________

Atactic

Isotactic

Multitactic

Syndiotactic

3. The thermoplastic is ____________

Held by a covalent bond

Insoluble

Cross-linked

Amorphous

4. Which of the following is not a potential application of dendrimer?

Molecular sensors

Viscosity modifier

Temperature modifier

Drug delivery system

5. The polymerisation in which propagating centers do not undergo either transfer or termination reactions is called ____________

Living polymerisation

Addition polymerisation

Dead polymerisation

Co-polymerisation

6. The softening temperature of HDPE is ____________

135⁰C

20⁰C

85⁰C

150⁰C

7. The C-Cl dipole makes PVC a polymeric polar molecule.

False

True

8. Which of the following is not the essential structural requirement of an elastomer?

Occasional cross-linking

Long flexible chains

Rigidity in structure

Weak intermolecular forces

9. Which of the following has the best resistance to oils?

Nitrile rubber

Natural rubber

Neoprene

Styrene rubber

10. Select the incorrect option from the following option.

Miscible blends are usually clear

Immiscible blends are usually opaque

Immiscible blends exhibit a single glass transition temperature (T_g) intermediate between those of individual components

Immiscible blends exhibit separate T_g’s characteristics of each component