Engineering Questions with Answers - Multiple Choice Questions
Applied Chemistry MCQ – Properties of Polymers
Polymeric molecules __________ a definite crystalline structure.
b) Do not have
c) Completely having
d) Partially having
Explanation: The polymeric molecules do not have a definite crystalline structure. The non-polymeric molecules have a definite crystalline structure.
The polymer is 100% crystalline.
Explanation: No polymer is 100% crystalline or 100% amorphous. A polymer is a mixture of 60% crystalline and 40% amorphous.
As the crystallinity increases The brittleness of the polymer _________
d) Remains constant
Explanation: As the crystallinity of the polymer increases then the brittleness of the polymer also increases. The strength and chemical resistance of the polymers also increases.
A polymeric molecules possess the molecular weight _____________
c) That cannot be determined
d) May be determined
Explanation: When polymerisation takes place, the growing polymeric chains are terminated at different sizes of molecules. So, as a result the polymeric molecules have different molecular weights.
Weight average molecular weight __________ on the weight of molecules in a polymer.
c) Partially dependent
d) Neither dependent nor independent
Explanation: Weight average molecular weight depends on the weight of the molecules of each type and determined by making use of colloidal properties.
The polymer absorbs ________ and swells in size.
a) Ethyl alcohol
Explanation: The polymer absorbs the water and swells in size. Slowly polymer goes into the solution viscous polymer solution which is heterogeneous.
___________ is the property of recovering original shape after the removal of deforming strain.
a) Rigidity modulus
b) Youngs modulus
d) Bulk modulus
Explanation: The elasticity is the property of recovering the original shape after removal of deforming strain. Natural rubber possess high elasticity due to the coiled helix structure of poly isoprene.
The impact strength is measured as _________
Explanation: The impact strength is measured as the toughness. Below the glass transition temperature, the polymers break.
If the polymer is in the room temperature then it is ___________
b) Viscofluid state
Explanation: The effect of heat on polymer is high. If the temperature changes, the state of the polymer will be changed.
The strength of the polymer increases with ________ in molecular weight.
c) No change
d) Slightly decrease
Explanation: The strength of the polymer increases with an increase in the molecular weight. The inter molecular attraction, presence of polar groups and chain length increases the strength.