3. Chemical Kinetics

*नोट: यह सेक्शन रिवीजन के लिए है। अपना ज्ञान परखने के लिए ऊपर दिए गए क्विज़ में भाग लें।

1. The change in concentration of a reactant or product in a specific time interval is called?
   A) Rate  |  B) Average rate  |  C) Instantaneous rate  |  D) Rate constant
2. The unit of rate constant (K) for a first-order reaction is?
   A) mol L⁻¹ s⁻¹  |  B) s⁻¹  |  C) mol L⁻¹  |  D) L mol⁻¹ s⁻¹
3. What is the unit of rate constant (K) for a zero-order reaction?
   A) mol L⁻¹ s⁻¹  |  B) s⁻¹  |  C) L mol⁻¹ s⁻¹  |  D) mol s⁻¹
4. Radioactive decay is a reaction of which order?
   A) Zero  |  B) First  |  C) Second  |  D) Third
5. What is the rate of reaction called when the concentration of reactants is unity (1)?
   A) Average rate  |  B) Rate constant  |  C) Temperature coefficient  |  D) Activation energy
6. What will be the order of the reaction with rate law r = K[A]⁰ [B]⁰?
   A) First  |  B) Second  |  C) Zero  |  D) Third
7. The energy required to bring the reactant molecules to the threshold energy is?
   A) Resonance energy  |  B) Activation energy  |  C) Frequency energy  |  D) Average energy
8. What is the effect of increasing temperature on the rate of reaction?
   A) Decreases  |  B) Increases  |  C) Remains constant  |  D) Becomes zero
9. What is the molecularity of unimolecular reactions?
   A) 0  |  B) 1  |  C) 2  |  D) 3
10. The value of rate constant (K) depends on?
    A) Concentration  |  B) Time  |  C) Temperature  |  D) Volume
11. The relationship between t½ and initial concentration [A] for a zero-order reaction is?
    A) t½ ∝ [A]  |  B) t½ ∝ 1/[A]  |  C) t½ ∝ [A]²  |  D) Does not depend
12. Molecularity of a reaction cannot be?
    A) 1  |  B) 2  |  C) 3  |  D) Zero
13. Threshold Energy is equal to?
    A) Activation energy + Average energy  |  B) Activation energy - Average energy  |  C) Rate constant + Temp  |  D) Only activation energy
14. Collision frequency means the number of?
    A) Collisions per second  |  B) Product amount  |  C) Decrease in concentration  |  D) Increase in temperature
15. The order of photochemical reactions is generally?
    A) Zero  |  B) One  |  C) Two  |  D) Three
16. The change in concentration at any specific instant of time is called?
    A) Rate  |  B) Average rate  |  C) Instantaneous rate  |  D) Rate constant
17. What is the unit of rate of reaction?
    A) mol L⁻¹  |  B) mol s⁻¹  |  C) mol L⁻¹ s⁻¹  |  D) s⁻¹
18. An example of a pseudo first-order reaction is?
    A) Inversion of cane sugar  |  B) Formation of HCl  |  C) Dissociation of HI  |  D) Decomposition of NH3
19. Hydrogenation of ethene is a reaction of which order?
    A) Zero  |  B) First  |  C) Second  |  D) Third
20. The value of order of reaction can be?
    A) Zero  |  B) Fractional  |  C) Integer  |  D) All of the above
21. If the concentration of reactants is made 3 times, the rate increases 9 times. The order will be?
    A) Zero  |  B) 2  |  C) 1  |  D) 3
22. If doubling the concentration has no effect on the rate, the order will be?
    A) Zero  |  B) One  |  C) Two  |  D) Three
23. In the rate law r = K[A]¹ [B]², if A is doubled, the rate will be?
    A) 2 times  |  B) 4 times  |  C) Half  |  D) None
24. The rate of a complex reaction is determined by which step?
    A) Fastest step  |  B) Average step  |  C) Slowest step  |  D) Final step
25. Reactions which have molecularity 2 but order 1 are called?
    A) Simple  |  B) Pseudo unimolecular  |  C) Zero order  |  D) Termolecular
26. On increasing the temperature of a reaction by 10°C, the rate becomes approximately?
    A) 4 times  |  B) Half  |  C) Constant  |  D) 2 times
27. The ratio of rate constants at a difference of 10 K temperature is called?
    A) Arrhenius coefficient  |  B) Van't Hoff coefficient  |  C) Temperature coefficient  |  D) Rate coefficient
28. Alkaline hydrolysis of ethyl acetate is a reaction of which order?
    A) Zero  |  B) Second  |  C) First  |  D) Third
29. If making the concentration 4 times makes the rate 2 times, the order is?
    A) Zero  |  B) 1/2  |  C) 1  |  D) 2
30. Which of the following is not a zero-order reaction?
    A) Formation of HCl from H2+Cl2  |  B) Decomposition of NH3 on Pt  |  C) Dissociation of HI on Au  |  D) Decomposition of N2O5
31. How does a catalyst increase the rate of reaction?
    A) By increasing energy  |  B) By decreasing activation energy  |  C) By reducing collisions  |  D) By increasing concentration
32. The rate law of a reaction is r = K[A]^(1/2) [B]^(3/2). The overall order will be?
    A) 0  |  B) 1  |  C) 2  |  D) 3
33. The unit of K for a second-order reaction is?
    A) s⁻¹  |  B) mol L⁻¹ s⁻¹  |  C) L mol⁻¹ s⁻¹  |  D) mol⁻² s⁻¹
34. The molecularity of a reaction is always?
    A) Integer  |  B) Fractional  |  C) Zero  |  D) Negative
35. The sum of the powers of the concentration terms in the rate law equation is called?
    A) Molecularity  |  B) Order  |  C) Rate constant  |  D) Threshold energy
36. If the rate law for the slowest step is r = K[NO2]², then the order of the overall reaction is?
    A) 1  |  B) 2  |  C) 3  |  D) 0
37. Hydrolysis of an ester in acidic medium represents?
    A) Second order  |  B) Zero order  |  C) Pseudo first order  |  D) Third order
38. If in rate law r = K[A]^x [B]^y, x+y = 2.5, then the order is?
    A) Integer  |  B) Zero  |  C) Fractional  |  D) Negative
39. The value of temperature coefficient is generally between?
    A) 1-2  |  B) 2-3  |  C) 3-4  |  D) 4-5
40. On increasing the temperature, the rate constant?
    A) Increases exponentially  |  B) Increases linearly  |  C) Decreases  |  D) Remains constant
41. t½ of a first-order reaction is 0.0693 min, the value of K will be?
    A) 10 s⁻¹  |  B) 10 min⁻¹  |  C) 0.1 min⁻¹  |  D) 100 min⁻¹
42. Rate law is r = K[A]² [B]⁻¹, what is its order?
    A) 1  |  B) 2  |  C) -1  |  D) 0
43. The time required for 99.9% completion of a first-order reaction is of t½?
    A) 2 times  |  B) 10 times  |  C) Half  |  D) 3 times
44. If doubling the concentration has no effect on t½, the order is?
    A) Zero  |  B) First  |  C) Second  |  D) Third
45. If halving the concentration halves t½, the order is?
    A) 0  |  B) 1  |  C) 2  |  D) 3
46. If doubling the concentration halves t½, the order is?
    A) 0  |  B) 1  |  C) 2  |  D) 3
47. For the rate law r = K[H2] [Br2]^(1/2), the value of order will be?
    A) 1  |  B) 1.5  |  C) 2  |  D) 0.5
48. On doubling the concentration of reactants, the rate of a first-order reaction will be?
    A) 4 times  |  B) 2 times  |  C) Half  |  D) 1/4 times
49. If the unit of K is L² mol⁻² s⁻¹, what will be the order of the reaction?
    A) 1  |  B) 2  |  C) 3  |  D) 0
50. What is the overall order for the rate law r = K[A]^(3/2) [B]^(-1/2)?
    A) 1  |  B) 2  |  C) 0.5  |  D) 1.5
51. The time required for 90% completion is approximately how many times of t½?
    A) 2  |  B) 3.3  |  C) 10  |  D) 4.4
52. If K = 2.303 x 10⁻³ s⁻¹, the value of t½ will be?
    A) 300 s  |  B) 1000 s  |  C) 693 s  |  D) 460 s
53. The time required for completion of a zero-order reaction is?
    A) t½  |  B) 2 x t½  |  C) 3 x t½  |  D) Infinite
54. The slope of the graph between ln K and 1/T is?
    A) -Ea/R  |  B) Ea/R  |  C) R/Ea  |  D) -R/Ea
55. For an n-th order reaction, the general unit of K is?
    A) (mol/L)^(1-n) s⁻¹  |  B) (mol/L)^(n-1) s⁻¹  |  C) mol L⁻¹ s⁻¹  |  D) s⁻¹
56. The rate of a first-order reaction is 2 x 10⁻⁵ at 0.1 M, K will be?
    A) 2 x 10⁻⁴  |  B) 2 x 10⁻³  |  C) 2 x 10⁻⁵  |  D) 5 x 10⁻⁴
57. For the reaction A + 2B → C, rate = K[A][B], the overall order will be?
    A) 1  |  B) 2  |  C) 3  |  D) 0
58. If making the concentration 3 times increases the rate 27 times, the order is?
    A) 1  |  B) 2  |  C) 3  |  D) 0
59. When activation energy (Ea) is zero, the rate constant (K) will be equal to?
    A) Zero  |  B) Infinity  |  C) Arrhenius factor (A)  |  D) 1
60. The time for 75% completion of a first-order reaction is?
    A) 2 x t½  |  B) 3 x t½  |  C) 1.5 x t½  |  D) 10 x t½