NEET Chemistry Chapter Wise Mock Test – Chemical Kinetics
For the reaction, 2A + B—> Products; the active mass of B is kept constant, and that of A is doubled. The rate of reaction will be then
(a) decrease 4 times
(b) decrease 2 times
(c) increase 4 times
(d) increase 2 times
A drop of solution (volume = 0.05 mL) contains 60.0x 10-7 molof H+ . If the rate of disappearance of H+ is 6.0x 105mol/Ls, how long will it take for H+ to disappear fro the drop?
(a) 8.0 x 10-8s
(b) 2.0 x 10-8s
(d) 2.0 x 10-2s
if a certain reaction is first order with respect to A, second order with respect to B and zero order with respect to C then what is the order of reaction?
For a reaction between A and B, the initial rate of reaction is measured for various initial concentrations of A and B. The data provided areThe overall order of the reaction is
(c) two and half
The rate constant of a zero order reaction is 0.2 mol dm-3 h-1 . If the concentration of the reactant after 30 min is 0.05 mol dm-3. Then, its initial concentration would be,
(a) 0.01 mol dm-3
(b) 0.15 mol dm-3
(c) 0.25 mol dm-3
(d) 4.00mol dm-3
The half-life period for zero order reaction A-—> Product; is 100 min. How long will it take in 80% completion?
(a) 80 min
(b) 160 min
(c) 100 min
(d) 200 min
For a reaction aA —» x P, when [A] = 2.2 mM, the rate was found to be 2.4 m Ms-1. On reducing concentration of A to half, the rate changes to 0.6 m Ms-1. The order of reaction with respect to A is
In the reaction, 2N205—> 4N02 + 02 , initial pressure is 500 atm and rate constant k is 3.38 x 10-5s-1. After 10 min, the final pressure of N205 is
(a) 490 atm
(b) 250 atm
(c) 480 atm
(d) 420 atm
A first order reaction is 50% completed in 1.26 x 1014 s. How much time would it take for 100% completion?
(a) 1.26 x 1015s
(b) 2.52 x 1014s
(c) 2.52 x 1025s
The value of rate constant of a pseudo first order reaction
(a) depends on the concentration of reactants present in small amount
(b) depends on the concentration of reactants present in excess
(c) is independent of the concentration of reactants
(d) depends only on temperature
For a first order reaction, the concentration changes s; from 0.8 to 0.4 in 15 min. The time taken for the $ concentration to change from 0.1 M to 0.025 M is it
(a) 30 min
(b) 15 min
(c) 7.5 min
(d) 60 min
t1/4 can be taken as the time taken for the concentration of a reactant to drop to 3/4 th of its initial value. If the rate constant for a first order reaction is k, the t1/4 can be Witten as
A first order reaction is 75% complete after 32 min. When was 50% of the reaction completed?
(a) 16 min
(b) 8 min
(c) 4 min
(d) 32 min
The concentration of reactant X decreases from 0.1 M to 0,005 M in 40 min. If the reaction follows first order kinetics, the rate of reaction when concentration of X is 0.01 M will be
(a) 1.73x 10-4 M mint-1
b ) 3.47 x 10-4 M min-1
(c) 3.47 x 10-5 M min-1
(d) 7.50 xIO-4 min-1
Sucrose decomposes in acid solution into glucose and fructose according to the first order rate law, with f1/2=3.00h. What fraction of sample of sucrose remains after 8 h?
(a) 1.023 M
(b) 0.8725 M
(c) 0.023 M
(d) 0.1576 M
The rate of first order reaction is 1.5x 10-2 mol L-1 min-1 at 0.5 M concentration of the reactant. The half-life of the reaction is
(a) 0.383 min
(b) 23.1 min
(c) 8.73 min
(d) 7.53 min
For a first order reaction, A >B, the reaction rate at reactant concentration of 0.01 M is found to be 2.Ox 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
The half-life of the reaction; ‘N205 > 2N0+1/202; is 2.4 h. Starting with 10.8 g of N2O5 , how much oxygen will be obtained after period of 9.6 h?
(a) 1.5 L
(b) 3.36 L
(c) 1.05 L
(d) 0.07 L
After how many seconds will the concentration of the reactant in a first order reaction be halved if tHevrate constant is 1.155 x 10-3 s-1?
The ratio of the times of 99.9% of the reaction to complete and half of the reaction to complete is .,.
The activation energy of a reaction is 9 kcal/mol. The . increase in the rate constant when its temperature is raised from 295 to 300 K is approximately
The rate constant of a reaction at temperature 200 K is 10 times less than the rate constant at 400 K. What is the activation energy (Ea) of the reaction?
(a) 1842.4 R
(b) 921.2 R
(c) 460.6 R
(d) 230.3 R
Activation energy of a chemical reaction can be determined by
(a) evaluating rate constant at standard temperatures
(b) evaluating velocities of reaction at two different temperatures
(c) evaluating rate constant at two different temperatures
(d) changing concentration of reactants .
The temperature coefficient of most of the reactions lies between
(a) 1 and 3
(b) 2 and 3
(c) 1 and 4
(d) 2 and 4
For a reversible reaction, A⇔B, which one of the following statements is wrong from the given energy profile diagram?
(a) Activation energy of forward reaction is greater than backward reaction
(b) The forward reaction is endothermic
(c) The threshold energy is less than that of activation energy
(d) The energy of activation of forward reaction is equal to the sum of heat of reaction and the energy of activation of backward reaction
The rate constant is doubled when temperature increases from 27° C to 37° C. Activation energy in kJ is
Which of the following statements is in accordance with collision theory?
I. Rate is directly proportional to collision frequency.
II. Rate depends upon orientation of atoms.
III. Temperature determines the rate.
(a) Only III
(b) I and II
(c) II and III
(d) All of these
In the presence of a catalyst, activation energy of a reaction lowered by 2 kcal at 27°C. Hence, rate will be
(a) 20 times
(b) 28 times
(c) 14 times
(d) remain the same
When we increase temperature, the rate of reaction increase because of
(a) more number of collisions
(b) decrease in mean free path
(c) more number of energetic collisions
(d) less number of energetic collisions
Pick the appropriate choice about collision theory of reaction rates.
I. It explains the effect of temperature on rate of reaction
II. It assumes that the reactants must be in correct orientate to react.
III. It says rate depends upon the frequency at which reactants collide.
IV. The collisions having energy higher than the threshold value will give successful reactions.
The correct points are
(a) I, III and IV
(b) II and IV
(c) I and IV
(d) I. II, III and IV
Direction (Q. Nos. 42-43) In the following questions, more than one of the answers given may be correct. Select the correct answer and mark it according to the codes.
(a) 1,2 and 3 are correct
(b) 1 and 2 are correct
(c) 2 and 4 are correct
(d) 1 and 3 are correct
Select the correct statements with respect of zero order reaction.
1. The rate of the reaction is independent of temperature.
2. The rate of the reaction is independent of reactant concentration.
3. The rate constant of the reaction is independent of temperature.
4. The rate constant of the reaction is independent of reactant concentration.
For the first order reaction,
1. the degree of dissociation is equal to (1 – e-ktw).
2. a plot of reciprocal concentration of the reactant versus times gives a straight line.
3. the pre-exponential factor in the Arrhenius equation has the dimension of time, t-1.
4. the time taken for the completion of 75% reaction is thrice the 1/2 of the reaction
Direction (Q. NOS. 46-48) Each of these questions contains two statements: Assertion and Reason. Each of these questions also has four alternative choices, only one of which is the correct answer. You have to select one of the codes (a), (b), (c) and (d) given below.
(a) Assertion is true, Reason is true; Reason is the correct explanation of the Assertion
(b) Assertion is true, Reason is true; Reason is not the correct explanation of the Assertion
(c) Assertion is true, Reason is false .
(d) Assertion is false, Reason is true
Assertion The order of a reaction can have fractional -value.
Reason The order of a reaction cannot be written from balanced equation of a reaction.
Assertion Molecularity has no meaning for a complex reaction.
Reason The overall molecularity of a complex reaction is equal to the molecularity of the slowest step.
When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction is
(d) more than zero but less than first
What is the activation energy for a reaction if its rate doubles when temperature is raised from 20°C to 35°C? (R = 8.314 J-1 K-1)
(a) 269 kJ mol-1
(b) 34.7 kJ mol-1
(d) 15.1 kJ mol-1
(d) 342 kJ mol-1
A reaction having equal energies of activation for forward and reverse reaction has
(a) ΔG = 0
(b) Δ H= 0
(C)ΔH = ΔG=ΔS=0
(d) Δ S = 0
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) 256 times
(b) 512 times
(c) 64 times
(d) 128 times
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]2
(b) Rate = k[A]2 [B]2
(c) Rate = k[A] [B]
(d) Rate = k[A]2 [B]
2N205 (g) —> 4N02 (g) + 02(g) What is the ratio of the rate of rate of formation of N02?
(a) 1 : 2
(b) 2 : 1
(c) 1 : 4
(d) 4 : 1
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
For a first order reaction A—> B, the reaction rate at reactant concentration of 0.01 M is found to be 2.0x 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
Which one of the following statements for the order of a reaction is incorrect?
(a) Order is not influenced by stoichiometric coefficient of the reactants
(b) Order of reaction is sum of power to the concentration terms of reactants to express the rate of reaction
(c) Order of reaction is always whole number
(d) Order can be determined only experimentally
Half-life of a reaction is found to be inversely proportional to the cube of initial concentration. The order of reaction is
A schematic plot of In Keq versus inverse of temperature for a reaction is shown below:
The reaction must be
(a) highly spontaneous at ordinary temperature
(b) one with negligible enthalpy change
At a certain temperature, the first order rate constant, k1 is found to be smaller than the second order rate constant, k2. If the energy of activation, E, of the first order reaction is greater than energy of activation, E2 of the second order reaction then with increase in temperature
(a) will increase faster than k2, but always will remain less than k2
(b) k2 will increase faster than f1,
(c) k1, will increase faster than k2 and becomes equal to k2
(d) k1, will increase faster than k2 and becomes greater than k2
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