1. The ratio of the rate constant of a reaction at two temperatures differing by how much 0°C is called the temperature coefficient of the reaction?
(A). 2
(B). 100
(C). 20
(D). 10
(E). None of these
Answer: d
2. Which of the following is the Natural rubber?
(A). Acrylonitrile
(B). Ethylene glycol
(C). Butadiene
(D). Polyisoprene
(E). None of these
Answer: d
3. Not the essential structural requirement of an elastomer is ______________
(A). Rigidity in structure
(B). Weak intermolecular forces
(C). Long flexible chains
(D). Occasional cross-linking
(E). None of these
Answer: a
4. The method that is satisfactory just for a simple homogeneous reaction is _______________
(A). Graphical method
(B). Integration method
(C). Half-life period method
(D). Ostwald’s isolation method
(E). None of these
Answer: b
5. The amount of sulphur that is added always determines the extent of the stiffness of vulcanised rubber.
(A). False
(B). True
(E). None of these
Answer: b
6. At which of the following temperature the raw rubber is heated for the vulcanisation process?
(A). 0-10°C
(B). 10-50°C
(C). 100-140°C
(D). 50-100°C
(E). None of these
Answer: c
7. Which of the following is the incorrect statement?
(A). Raw rubber is durable
(B). Raw rubber is attacked by oxidizing agents
(C). In the organic solvents, it always undergoes swelling and disintegration
(D). The raw rubber is always weak and has very low tensile strength
(E). None of these
Answer: a
8. What is a zero-order reaction?
(A). The one whose rate increases with time
(B). The one in which one of the reactants is in large excess
(C). The one in which the rate is independent of the reactant’s concentration
(D). The one whose rate is not affected by time
(E). None of these
Answer: c
9. Which of the following is the tensile strength (kg/cm²) of vulcanised rubber?
(A). 200
(B). 5000
(C). 500
(D). 2000
(E). None of these
Answer: d
10. Which of the following is the percentage of butadiene and styrene in Buna-S?
(A). 75% and 25% respectively
(B). 60% and 40% respectively
(C). 80% and 20% respectively
(D). 50% each
(E). None of these
Answer: a
11. Which of the following is the structural formula of isoprene?
(A). 2-benzyl-1,3-butadiene
(B). 3-benzyl-1,2-butadiene
(C). 2-methyl-1,3-butadiene
(D). 3-methyl-1,2-butadiene
(E). None of these
Answer: c
12. What happens to the half-life period of a first-order reaction as it varies with temperature?
(A). It remains the same
(B). It increases
(C). It decreases
(D). Both increase as well as decrease
(E). None of these
Answer: a
13. The temperature dependence of reaction rates can be studied by plotting a graph between which of the following?
(A). Concentration of products and temperature
(B). Rate constant and temperature
(C). Concentration of reactants and temperature
(D). Rate of catalysis and temperature
(E). None of these
Answer: b
14. According to Arrhenius’ equation, rate constant (k) is proportional to which of the following?
(A). Activation Energy (E)
(B). e¹/ᴱ
(C). e⁻ᴱ
(D). eᴱ
(E). None of these
Answer: b
15. At 20°C, for a reaction having the activation energies in the presence and absence of a catalyst as 50 kJ/mol and 75 kJ/mol, the rate of reaction increases ______________ times.
(A). 10000
(B). 30000
(C). 1000
(D). 50000
(E). None of these
Answer: b
16. The method that is used for determining the order of the reaction in which two or more reactants take part is _____________
(A). Ostwald’s isolation method
(B). Integration method
(C). Graphical method
(D). Half-life period method
(E). None of these
Answer: a
17. In the vulcanisation process, with which of the following is the raw rubber heated?
(A). Oxygen
(B). Calcium
(C). Carbon
(D). Sulphur
(E). None of these
Answer: d
18. The incorrect statement is that vulcanised rubber has ______________
(A). High elasticity
(B). Only slight tackiness
(C). Excellent resilience
(D). Tensile strength 10 times more than raw rubber
(E). None of these
Answer: a