This set of Applied Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Plastics”.
1. Plastics are the materials obtained by mixing the __________ with the other ingredients which impart special engineering properties.
d) Any polymer
Explanation: Plastics are the materials obtained by mixing the resin with the other ingredients having special engineering properties. A resin is the polymerisation and forms the major part of the plastics.
2. Plastics are ________ in weight.
a) Very heavy
Explanation: Plastics are light in weight. They have good thermal and electrical insulation. So, they do not conduct electricity.
3. The fabrication cost is __________ for plastics.
d) Very high
Explanation: The fabrication cost of the plastics is low. It has easy workability. It is chemically inert. It do not react with any other compounds.
4. The abrasion resistance of the plastic is ____________
b) Very low
Explanation: The abrasion resistance of the plastic is high. Th plastic has the dimensional stability. It is impermeable to water.
5. The plastics are _________
a) Semi conductors
c) Conducts at above room temperature only
Explanation: The plastics are very good insulators. They are considered as the good engineering materials due to the this reason also.
6. Plastic resin is used in the paint industry as _________
b) Ion exchanger
Explanation: Plastic is used in the paint industry as the ion exchanger in purification of the water for boilers and as good building materials.
7. How many types of plastic resins are there?
Explanation: The plastic resins are classified into two types. They are thermo plastic resins and thermo setting resins.
8. Thermo plastics becomes ________ on heating.
Explanation: On heating the thermo plastic resins, they become soft and on cooling they become rigid reversibly. The thermo setting resins are moulded on heating.
9. The heating and cooling of the thermo plastics _________the chemical nature.
b) Do not alters
c) Alters slightly
d) May be alters
Explanation: The heating and cooling of the thermo plastics do not alters the chemical nature of these resins because the changes involved are purely of physical nature.
10. Thermo setting plastics are formed by_________
a) Step polymerisation
b) Suspension polymerisation
c) Emulsion polymerisation
d) Co-ordination polymerisation
Explanation: Thermo setting plastics are formed by the step polymerisation. The thermo plastic resins are formed by chain polymerisation.
11. The thermo setting resins have three dimensional network structures.
Explanation: The thermo setting resins have three dimensional network structures. The thermo plastics consists of long chain linear polymers.
12. Thermo setting resins are __________
d) Less brittle
Explanation: Thermo setting resins are hard. They are strong in nature and they are more brittle.
13. The thermo plastics resins are usually soluble in _________
a) Organic solvents
b) Only in some organic solvents
c) Polar solvents
d) Only in water
Explanation: The thermo plastics resins are usually soluble in organic solvents. The thermo setting resins are insoluble in organic solvents.
14. Which of the following is a thermo setting resins?
b) Polyvinyl chloride
c) Polyvinyl cyanide
Explanation: The Bakelite comes under the thermo setting resins. The polyethene and poly vinyl chloride comes under the thermo plastic resins.
15. In thermo plastic resins the force of attraction can be break easily by ____________
c) Both heat and pressure
d) Neither heat nor pressure
Explanation: In thermo plastic resins the force of attraction can be break easily by both the heat and pressure. These can be reshaped but the thermo setting resins cannot be reshaped.
Sanfoundry Global Education & Learning Series – Applied Chemistry.
To practice all areas of Applied Chemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.