NEET Chemistry Chemical Kinetics MCQs Set B

Question:  For a gaseous phase reaction 2A + B₂→ 2AB, the following rate data was obtained at 300K

The rate constant for the reaction is

• a) 0.5 mol^–1 min^–1 litre
• b) 0.8 mol^–1 min^–1 litre 
• c) 1.5 mole^–1 min^–1 litre 
• d) 2 mol^–1 min^–1 litre

Answer:  0.8 mol^–1 min^–1 litre 

Question:  Inversion of a sugar follows first order rate equation which can be followed by noting the change in rotation of the plane of polarization of light in the polarimeter. If r_∞, r_t and r₀ are the rotations at t = ∞, t = t and t = 0 then, first order reaction can be written as

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which of the following is correct?

• a)

  

• b) For zero order t_1/2 is inversely proportional to initial concentration
• c) Catalyst decreases the activation energy
• d) All of these

Answer: Catalyst decreases the activation energy

Question:  The rate constant of a reaction is 1.5 × 107 s^–1 at 50°C and 4.5 × 107 s^–1 at 100°C. What is the value of activation energy?

• a) 2.2 × 10³ J mol^–1 
• b) 2300 J mol^–1
• c) 2.2 × 10⁴ J mol^–1 
• d) 220 J mol^–1

Answer: 2.2 × 10⁴ J mol^–1 

Question:  In Arrhenius equation,

A may not be termed as rate constant

• a) When 100% reactant will convert into the product
• b) When the temperature becomes infinite
• c) When the fraction of molecule crossing over the energy barrier becomes unity
• d) At very low temperature

Answer: At very low temperature

Question:  The rate constant of the production of 2B(g) by the reaction,

A 1 : 1 molar ratio of A to B in the reaction mixture is attained after

• a) 26.25 minute
• b) 27.25 minute
• c) 28.25 minute
• d) 0 minute

Answer: 27.25 minute

Question:   Two substances A and B are present such that [A]₀= 4[B]₀ and half life of A is 5 minute and that of B is 15 minute. If they start decaying at the same time following first order kinetics how much time will the concentration of both of them would be the same?

• a) 15 minute
• b) 10 minute
• c) 5 minute
• d) 12 minute

Answer: 15 minute

Question: If the rate of reaction increases by 27 times, when temperature is increased by 30 K, then temperature coefficient of the reaction is

• a) 3
• b) 2
• c) 1
• d) 2.5

Answer: 3

Question:  The reaction A —→B follows first order kinetics. The time taken for 0.80 mole of A to produce 0.60 mole of B is 1 hour. What is the time taken for conversion of 0.90 mole of A to produce 0.675 mole of B?

• a) 1 hour
• b) 30 min
• c) 15 min
• d) 5 min

Answer: 1 hour

Question:  If,

find B%

• a) 25%
• b) 50%
• c) 75%
• d) 80%

Answer: 25%

Question:  The rate constant of the reaction A—→ B is 0.6 × 10^–3 mole per second. If the concentration of A is 5 M, then concentration of B after 20 minutes is 

• a) 0.36 M
• b) 0.72 M
• c) 1.08 M
• d) 3.60 M

Answer: 0.72 M

Question: The activation energy of a reaction can be determined from the slope of which of the following graphs?

• a)

  

• b) In K vs T
• c)

  

• d)

  

Answer:

Question: When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction is

• a) More than zero but less than first
• b) Zero
• c) First
• d) Second

Answer: First

Question: A reaction having equal energies of activation for forward and reverse reactions has

• a) ΔG = 0
• b) ΔH = 0
• c) ΔH =ΔG =ΔS = 0 
• d) ΔS = 0

Answer: ΔH = 0

Question:  In a zero order reaction for every 10° rise of temperature, the rate is doubled. If the temperature is increased from 10°C to 100°C, the rate of the reaction will become 

• a) 64 times
• b) 128 times
• c) 256 times
• d) 512 times

Answer: 512 times

Question:  What is the activation energy for a reaction if its rate doubles when the temperature is raised from 20°C to 35°C? (R = 8.314 J mol^–1K^–1) 

• a) 269 kJ mol^–1
• b) 34.7 kJ mol^–1 
• c) 15.1 kJ mol^–1 
• d) 342 kJ mol^–1

Answer: 34.7 kJ mol^–1 

Question:  In a reaction, A + B → Product, rate is doubled when the concentration of B is doubled, and rate increases by a factor of 8 when the concentrations of both the reactants (A and B) are doubled, rate law for the reaction can be written as 

• a) Rate = k[A] [B]
• b) Rate = k[A]²[B]
• c) Rate = k[A] [B]²
• d) Rate = k[A]²[B]²

Answer:  Rate = k[A]²[B]

Question: Which one of the following statements for the order of a reaction is incorrect?

• a) Order of reaction is always whole number
• b) Order can be determined only experimentally
• c) Order is not influenced by stoichiometric coefficient of the reactants
• d) Order of reaction is sum of power to the concentration terms of reactants to express the rate of reaction

Answer: Order of reaction is always whole number

Question: The unit of rate constant for a zero order reaction is

• a) L² mol^–2 s^–1
• b) s^–1 
• c) mol L^–1 s^–1 
• d) L mol^–1 s^–1

Answer: mol L^–1 s^–1 

Question:  The half life of a substance in a certain enzyme- catalysed reaction is 138 s. The time required for the concentration of the substance to fall from 1.28 mg L^–1 to 0.04 mg L^–1 is 

• a) 690 s
• b) 276 s
• c) 414 s
• d) 552 s

Answer: 690 s

Question:  For the reaction, N₂O₅(g) → 2NO₂ (g) + 1/2 O₂(g), the value of rate of disappearance of N₂O₅ is given as 6.25×10^–3 mol L^–1s^–1. The rate of formation of NO₂ and O₂ is given respectively as 

• a) 6.25 × 10^–3 mol L^–1s^–1 & 6.25 × 10^–3 mol L^–1s^–1
• b) 1.25 × 10^–2 mol L^–1s^–1 & 3.125 × 10^–3 mol L^–1s^–1
• c) 6.25 × 10^–3 mol L^–1s^–1 & 3.125 × 10^–3 mol L^–1s^–1
• d) 1.25 × 10^–2 mol L^–1s^–1 & 6.25 × 10^–3 mol L^–1s^–1

Answer: 1.25 × 10^–2 mol L^–1s^–1 & 3.125 × 10^–3 mol L^–1s^–1

Question:  For an endothermic reaction, energy of activation is E_a and enthalpy of reaction is ΔH (both of these in kJ/mol). Minimum value of E_a will be 

• a) Less than ΔH
• b) Equal to ΔH
• c) More than ΔH 
• d) Equal to zero

Answer:  More than ΔH 

Question:  During the kinetic study of the reaction, 2A+B→C+D, following results were obtained

Based on the above data which one of the following is correct ? 

• a) Rate = K[A]² [B] 
• b) Rate = K[A][B]
• c) Rate = K[A]² [B]²   
• d) Rate = K[A][B]²

Answer: Rate = K[A][B]²

Question:  The rate of the reaction, 2NO + Cl₂—→2NOCl is given by the rate equation rate = k[NO]₂[Cl₂] The value of the rate constant can be increased by 

• a) Increasing the temperature
• b) Increasing the concentration of the Cl₂
• c) Increasing the concentration of NO
• d) Doing all of these

Answer: Increasing the temperature

Question:  For the reaction, N₂+ 3H₂→2NH₃, 

• a) 4×10^–4 mol L^–1 s^–1
• b) 6×10^–4 mol L^–1 s^–1
• c) 1×10^–4 mol L^–1 s^–1
• d) 3×10^–4 mol L^–1 s^–1

Answer:  3×10^–4 mol L^–1 s^–1

Question:   In the reaction,

The rate of appearance of bromine (Br₂) is related to rate of disappearance of bromide ions as following

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Half life period of a first-order reaction is 1386 seconds. The specific rate constant of the reaction is

• a) 0.5 × 10^–2 s^–1
• b) 0.5 × 10^–3 s^–1
• c) 5.0 × 10^–2 s^–1 
• d) 5.0 × 10^–3 s^–1

Answer:  0.5 × 10^–3 s^–1

Question:  For the reaction A + B —→ Products, it is observed that

(a) On doubling the initial concentration of A only, the rate of reaction is also doubled and

(b) On doubling the initial concentrations of both A and B, there is a change by a factor of 8 in the rate of the reaction.

The rate of this reaction is given by

• a) Rate = k [A] [B]² 
• b) Rate = k [A]²[B]²   
• c) Rate = k [A] [B]
• d) Rate = k[A]²[B]

Answer:  Rate = k [A] [B]² 

Question:  The rate constants k₁ and k₂ for two different reactions are 10¹⁶ e^–2000/T and 10¹⁵ e^–1000/T respectively. The temperature at which k₁= k₂ is

• a)

  

• b) 1000 K
• c)

  

• d) 2000 K

Answer:

Question:  The bromination of acetone that occurs in acid solution is represented by this equation

These kinetic data were obtained for given reaction concentrations

Based on these data, the rate equation is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

More Questions.............................

Question:   In a first-order reaction A —→ B, if K is rate constant and initial concentration of the reactant A is 0.5M then the half-life is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:   The reaction of hydrogen and iodine monochloride is given as

H_2(g)+ 2ICI_(g)—→2HCl_(g)+ I_2(g)

This reaction is of first order with respect to H_2(g)and ICI_(g) , following mechanisms were proposed

Mechanism A:

H_2(g)+ 2ICI_(g)—→2HCl_(g)+ I_2(g)

Mechanism B:

H_2(g)+ ICI_(g)—→ HCl_(g)+ HI_(g); slow

HI_(g)+ ICI_(g)—→HCl_(g)+ I_2(g); fast

Which of the above mechanism(s) can be consistent with the given information about the reaction?

• a) A only
• b) B only
• c) Both (1) and (2)
• d) Neither (1) nor (2)

Answer: B only

Question: If 60% of a first order reaction was completed in 60 minutes, 50% of the same reaction would be completed in approximately (log 4 = 0.60, log 5 = 0.69)

• a) 40 minutes
• b) 50 minutes
• c) 45 minutes
• d) 60 minutes

Answer: 45 minutes

Question:  For the reaction, 2A + B —→3C + D. Which of the following does not express the reaction rate?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:  Consider the reaction, N₂(g) + 3H₂(g) —→2NH₃(g). The equality relationship between   is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:   For a first order reaction A—→ B, the reaction rate at reactant concentration of 0.01 M is found to be 2.0 ×10^–5 mol L^–1 s^–1. The half life period of the reaction is 

• a) 220 s
• b) 30 s
• c) 300 s
• d) 347 s

Answer: 347 s

Question:  A nuclide of an alkaline earth metal undergoes radioactive decay by emission of three α-particles in succession. The group of the periodic table to which the resulting daughter element would belong is

• a) Group 14
• b) Group 16
• c) Group 4
• d) Group 6

Answer: Group 14

Question: The rate of reaction between two reactants A and B decreases by a factor of 4, if the concentration of reactant B is doubled. The order of this reaction with respect to reactant B is

• a) –1
• b) –2
• c) 1
• d) 2

Answer: –2

Question: A reaction is 50% complete in 2 hours and 75% complete in 4 hours. The order of reaction is

• a) 0
• b) 1
• c) 2
• d) 3

Answer: 1

Question: The half life time of 2g sample of radioactive nuclide ‘X’ is 15 min. The half life time of 1g sample of X is

• a) 7.5 min
• b) 15 min
• c) 22.5 min
• d) 30 min

Answer: 15 min

Question:  The rate of the reaction : 2N₂O₅ —→ 4NO₂+ O₂ can be written in three ways :

The relationship between k and k’ and between k and k” are

• a) k’ = 2k; k” = 2k 
• b) k’= k; k” = k 
• c) k’ = 2k; k” = k
• d)

  

Answer:

Question:  For the following reaction 

Which one of the following is not affected by the addition of catalyst?

• a) Rate of forward reaction
• b) Rate of backward reaction
• c) Time required to reach the equilibrium
• d) Spontaneity

Answer: Spontaneity

Question:  A chemical reaction proceeds into the following steps

The rate law for the overall reaction is

• a) Rate = k[A]²  
• b) Rate = k[B]²     
• c) Rate = k[A][B]
• d) Rate = k[A]²[B]

Answer:  Rate = k[A]²[B]

Question:  The data for the reaction A + B —→ C, is

The rate law corresponds to the above data is

• a) Rate = k[A][B]³ 
• b) Rate = k[A]²[B]² 
• c) Rate = k[B]³
• d) Rate = k[B]⁴

Answer:  Rate = k[B]³

Question:  Half-life for radioactive ¹⁴C is 5760 years. In how many years 200 mg of ¹⁴C will be reduced to 25 mg?

• a) 17280 years
• b) 23040 years
• c) 5760 years
• d) 11520 years

Answer: 17280 years

Question: A chemical reaction is catalyzed by a catalyst X. Hence X

• a) Reduces enthalpy of the reaction
• b) Does not affect equilibrium constant of reaction
• c) Decreases rate constant of the reaction
• d) Increases activation energy of the reaction

Answer: Does not affect equilibrium constant of reaction

Question: The given reaction 2 FeCl₃+ SnCl₂—→ 2 FeCl₂+ SnCl₄ is an example of

• a) Third order reaction
• b) First order reaction
• c) Second order reaction
• d) None of these

Answer: Third order reaction

Question:  The experimental data for the reaction

2A + B₂→ 2AB is

The rate equation for the above data is

• a) rate = k [A]² [B]²  
• b) rate = k [A]² [B]
• c) rate = k [B₂]       
• d) rate = k [B₂]²

Answer:  rate = k [B₂]       

Question: Carbon-14 dating method is based on the fact that

• a) Ratio of carbon-14 and carbon-12 is constant
• b) Carbon-14 is the same in all objects
• c) Carbon-14 is highly insoluble
• d) All of these

Answer: Ratio of carbon-14 and carbon-12 is constant

Question: Activation energy of a chemical reaction can be determined by

• a) Evaluating rate constants at two different temperatures
• b) Evaluating velocities of reaction at two different temperatures
• c) Evaluating rate constant at standard temperature
• d) Changing concentration of reactants

Answer: Evaluating rate constants at two different temperatures

Question: For a first-order reaction, the half-life period is independent of

• a) First power of final concentration
• b) Cube root of initial concentration
• c) Initial concentration
• d) Square root of final concentration

Answer: Initial concentration

Question:  The half-life of ₆C¹⁴, if its λ is 2.31 × 10^–4 year^–1, is

• a) 3.5 × 10⁴ years 
• b) 3 × 10³ years    
• c) 2 × 10² years    
• d) 4 × 10³ years

Answer:  3 × 10³ years    

Question: A 300 gram radioactive sample has a half life 3 hours. After 18 hours remaining quantity

• a) 4.68 gram
• b) 2.34 gram
• c) 3.34 gram
• d) 9.37 gram

Answer: 4.68 gram

Question: How enzymes increases the rate of reactions?

• a) By lowering activation energy
• b) By increasing activation energy
• c) By changing equilibrium constant
• d) By forming enzyme substrate complex

Answer: By lowering activation energy

Question:  For the reaction; 2N₂O₅→ 4NO₂+ O₂ rate and rate constant are 1.02 × 10^–4 Ms^–1 and 3.4 × 10^–5 s^–1 respectively, then concentration of N₂O₅ at that time will be (in molarity)

• a) 1.732
• b) 3
• c) 1.02 × 10^–4   
• d) 3.4 × 10⁵

Answer: 3

Question: A human body required 0.01 m activity of radioactive substance after 24 hours. Half life of radioactive substance is 6 hours. Then injection of maximum activity of radioactive substance that can be injected

• a) 0.08
• b) 0.04
• c) 0.16
• d) 0.32

Answer: 0.16

Question:  When a biochemical reaction is carried out in laboratory, outside the human body in absence of enzyme, then rate of reaction obtained is 10^–6 times, the activation energy of reaction in the presence of enzyme is

• a) 6/RT
• b) P is required
• c) Different from E_a obtained in laboratory
• d) Can’t say anything

Answer:  Different from E_a obtained in laboratory

Question:  3A → 2B, rate of reaction

is equal to

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:  2A → B + C

It would be a zero order reaction when

• a) The rate of reaction is proportional to square of conc. of A
• b) The rate of reaction remains same at any conc. of A
• c) The rate remains unchanged at any conc. of B and C
• d) The rate of reaction doubles if conc. of B is increased to double

Answer: The rate of reaction remains same at any conc. of A

Question:  The activation energy for a simple chemical reaction A →B is Ea in forward direction. The activation energy for reverse reaction

• a) Is negative of E_a
• b) Is always less than E_a
• c)  Can be less than or more than E_a
• d) Is always double of E_a

Answer:  Can be less than or more than E_a