JEE Questions for Chemistry Chemical Kinetics Quiz 3 - MCQExams.com

If 'a' and 't1/2' are initial concentration of reactant and half-life of a zero order reaction respectively, which of the following is correct ?
  • t1/2 ∝ 1/a
  • t1/2 ∝ a
  • t1/2 ∝ 1/a2
  • t1/2 ∝ a2
The rate constant of a reaction is found to be 3 × 10-3 mol L-1 min-1 . The order of the reaction is
  • zero
  • 1
  • 2
  • 1.5
Rate of a reaction can be expressed by following rate expression Rate = k[A]2 [B], if concentration of A is reduced by half by what times concentration of B is to be increased to have same rate of reaction ?
  • 4 times
  • 2 times
  • 1/4 times
  • 8 times
The rate constant of a first order reaction is 6.9 × 10-3 s -1. How much time will it take to reduce the initial concentration to its 1/ 8 th value ?
  • 100 s
  • 200 s
  • 300 s
  • 400 s
Which one of the following statement for order of reaction is not correct ?
  • Order can be determined experimentally
  • Order of reaction is equal to sum of the power of concentration terms in differential rate law
  • It is not affected with stoichiometric coefficient of the reactants
  • Order cannot be fractional
t1/4 can be taken as the time taken for the concentration of a reactant to drop to 3 / 4 of its initial value. If the rate constant for a first order reaction is k, the t1/4 can be written as
  • 0.75/k
  • 0.69/k
  • 0.29/k
  • 0.10/k
For the reaction A + B → C, it is found that doubling the concentration of A increases the rate by four times and doubling the concentration of B doubles the reaction rate. What is the overall order of the reaction ?
  • 4
  • 3/2
  • 3
  • 1
In a first order reaction, reactant concentration C varies with time t as
  • 1/ C increases linearly with t
  • log C decreases linearly with t
  • C decreases with 1/ t
  • log C decreases with 1/ t
Raw milk sours in about 4 h at 27°C, but in about 48 h in a refrigerator at 17°C. What is the activation energy for souring of milk?
  • 78.0 kJ mol-1
  • 46.21 kJ mol-1
  • 23.5 kJ mol-1
  • 80.8 kJ mol-1
A chemical reaction was carried out at 300 K and 280 K. The rate constants were found to be k1 and k2 respectively. Then
  • k2 ≈ 0.25 k1
  • k2 ≈ 0.5 k1
  • k2 ≈ 4 k1
  • k2 ≈ 2 k1
The rate of a reaction is doubled for every 10° rise in temperature. The increase in reaction rate as a result of temperature rise from 10° to 100° is
  • 112
  • 512
  • 400
  • 614
  • 100
The rate of a chemical reaction doubles for every 10° C rise of temperature. If the temperature is raised by 50° C, the rate of the reaction increases by about
  • 10 times
  • 24 times
  • 32 times
  • 64 times
Which of the following statement 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
  • Only III
  • Only I and II
  • Only II and III
  • All of these
If X is the total number of collisions which a gas molecule register with others per unit time under particular conditions, then the collision frequency of the gas containing N molecules per unit volume is
  • X / N
  • NX
  • 2NX
  • NX / 2

Chemistry-Chemical Kinetics-1561.png
  • K is equilibrium constant
  • A is adsorption factor
  • Ea is energy of activation
  • R is Rydberg constant
The efficiency of an enzyme in catalysing a reaction is due to its capacity
  • To form a strong enzyme substrate complex
  • To decrease the bond energy of all substrate molecules
  • To change the shape of the substrate molecule
  • To lower the activation energy of the reaction
A catalyst
  • Increases the average kinetic energy of reacting molecules
  • Increases the activation energy
  • Alters the reaction mechanism
  • Increases the frequency of collisions of reacting species
Which of the following is a first order reaction?

  • Chemistry-Chemical Kinetics-1563.png
  • 2)
    Chemistry-Chemical Kinetics-1564.png

  • Chemistry-Chemical Kinetics-1565.png

  • Chemistry-Chemical Kinetics-1566.png
Which of the following statements is incorrect?
  • The catalyst does not affect the equilibrium of a reaction
  • Reaction with higher activation energy has higher rate constant
  • In an exothermic reaction, the activation energy of the reverse reaction is higher than that of the forward reaction
  • Half – life period of a first order reaction is independent of initial concentration
A reaction involving two different ractants
  • can never be a first order reaction
  • can never be a second order reaction
  • can never be a unimolecular reaction
  • can never be a bimolecular reaction
The rate constant of a reaction increases with increase of temperature because
  • The activation energy increases
  • The population of activated molecules increases.
  • The activation energy decreases
  • The population of activated molecules decreases
In which of the following cases, does the reaction go farthest to completion?
  • k = 102
  • k = 10-2
  • k = 10
  • k = 1
If the half–time for a particular reaction is found to be constant and independent of the initial concentration of the reactants then reaction is of
  • first order
  • zero order
  • second order
  • none of these
The hydrolysis of methyl formate in acid solution has rate expression: rate = k [HCOOCH3] [H+], the balanced equation being HCOOCH3+H2O → HCOOH+CH3OH The rate law contains [H+] though the balanced equation does not contain [H+] because
  • more for convenience to express the rate law
  • H+ ion is a catalyst
  • H+ is an important constituent of any reaction
  • all acids contain H+ ions
According to the Arrhenius equation a straight line is to be obtained by plotting the logarithm of the rate constant of a chemical reaction (log k) against
  • T
  • log T
  • 1/T
  • log 1/T
The plot of concentration of the reactant versus time for a reaction is a straight with a negative slope. The reaction follows a
  • first order rate equation
  • zero order rate equation
  • second order rate equation
  • third order rate equation
The given reaction 2FeCl3 + SnCl2 → 2FeCl2 + SnCl4 is an example of
  • first order reaction
  • second order reaction
  • third order reaction
  • none of these
For a first–order reaction, the half life period is independent of
  • initial concentration
  • cube root of initial concentration
  • first power of final concentration
  • square root of final concentration
The activation energy of a reaction can be determined by
  • changing the concentrations of the reactants
  • evaluating the rate constant at standard temperature
  • evaluating the rate constant at two different concentrations
  • evaluating the rate constant at two different temperatures
  • by doubling the concentrations of the reactants
When we increase the temperature, the rate of reaction increases because of
  • more number of collisions
  • decrease in mean free path
  • more number of energetic electrons
  • less number of energetic electrons
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