201.
The reaction of hydrogen and iodine monochloride is given as $${H_2}\left( g \right) + 2ICl\left( g \right) \to $$ $$2HCl\left( g \right) + {I_2}\left( g \right)$$
This reaction is of first order with respect to $${H_2}\left( g \right)$$ and $$ICl\left( g \right),$$ following mechanisms were proposed
Mechanism $$A$$
$${H_2}\left( g \right) + 2ICl\left( g \right) \to $$ $$2HCl\left( g \right) + {I_2}\left( g \right)$$
Mechanism $$B$$
$${H_2}\left( g \right) + ICl\left( g \right) \to $$ $$HCl\left( g \right) + HI\left( g \right),{\text{slow}}$$
$$HI\left( g \right) + ICl\left( g \right) \to $$ $$HCl\left( g \right) + {I_2}\left( g \right),{\text{fast}}$$
Which of the above mechanism $$(s)$$ can be consistent with the given information about the reaction?
A
Only $$B$$
B
Both $$A$$ and $$B$$
C
Neither $$A$$ nor $$B$$
D
Only $$A$$
Answer :
Only $$B$$
202. If half-life of a substance is 5 yrs, then the total amount of substance left after 15 years, when initial amount is 64 grams is
A
16 grams
B
2 grams
C
32 grams
D
8 grams.
Answer :
8 grams.
203. The overall rate of a reaction is governed by
A
the rate of fastest intermediate step
B
the sum of the rates of all intermediate steps
C
the average of the rates of all the intermediate steps
D
the rate of slowest intermediate step
Answer :
the rate of slowest intermediate step
204.
For the reaction $$A + B \to C + D.$$ The variation of the concentration of the products is given by the curve
A
$$Z$$
B
$$Y$$
C
$$W$$
D
$$X$$
Answer :
$$Y$$
205.
A graph of volume of hydrogen released vs time for the reaction between zinc and dil. $$HCl$$ is given in figure. On the basis of this mark the correct option.
A
Average rate upto 40 seconds is $$\frac{{{V_3} - {V_2}}}{{40}}$$
B
Average rate upto 40 seconds is $$\frac{{{V_3} - {V_2}}}{{40 - 30}}$$
C
Average rate upto 40 seconds is $$\frac{{{V_3}}}{{40}}$$
D
Average rate upto 40 seconds is $$\frac{{{V_3} - {V_1}}}{{40 - 20}}$$
Answer :
Average rate upto 40 seconds is $$\frac{{{V_3}}}{{40}}$$
206. In a reaction, $$2X \to Y,$$ the concentration of $$X$$ decreases from $$0.50\,M$$ to $$0.38\,M$$ in $$10\,\min .$$ What is the rate of reaction in $$M\,{s^{ - 1}}$$ during this interval?
A
$$1 \times {10^{ - 4}}$$
B
$$4 \times {10^{ - 2}}$$
C
$$2 \times {10^{ - 2}}$$
D
$$1 \times {10^{ - 2}}$$
Answer :
$$1 \times {10^{ - 4}}$$
207. In the presence of an acid, the initial concentration of cane sugar was reduced from $$0.20$$ to $$0.10\,M$$ in 5 hours and from $$0.2$$ to $$0.05\,M$$ in 10 hours. The reaction is of :
A
Zero order
B
First order
C
Second order
D
Third order
Answer :
First order
208. The half-life of the reaction $$X \to Y,$$ following first order kinetics, when the initial concentration of $$X$$ is $$0.01\,mol\,{L^{ - 1}}$$ and initial rate is \[0.00352\,mol\,{{L}^{-1}}\,{{\min }^{-1}}\] will be
A
$$19.69\,\min .$$
B
$$1.969\,\min .$$
C
$$7.75\,\min .$$
D
$$77.5\,\min .$$
Answer :
$$1.969\,\min .$$
209. Which one of the following statements is not correct?
A
Catalyst does not initiate any reaction
B
The value of equilibrium constant is changed in the presence of a catalyst in the reaction equilibrium
C
Enzymes catalyse mainly biochemical reaction
D
Coenzymes increase the catalytic activity of enzyme
Answer :
The value of equilibrium constant is changed in the presence of a catalyst in the reaction equilibrium
210. In a reaction, $$2A \to $$ products, the concentration of $$A$$ decreases from $$0.50\,M$$ to $$0.38\,M$$ in $$10\,\min .$$ What is the rate of reaction $$\left( {{\text{in}}\,M\,{s^{ - 1}}} \right)$$ during this interval ?
A
$$0.012$$
B
$$0.024$$
C
$$2 \times {10^{ - 3}}$$
D
$$2 \times {10^{ - 4}}$$
Answer :
$$2 \times {10^{ - 4}}$$