Chemical Kinetics

CBSE Class 12 Chemistry · every board question from this chapter, 2022–2026 · 61 of them repeated across years

• Which of the following curve represents the first order reaction?2026asked 3×
• Identify the correct statement:2026asked 2×
• The order for the given reaction is: A + 2B → Products Rate =k[A]^1 / 2[ B]^12026asked 3×
• Which of the following represents the fraction of molecules with energies equal to or greater than E a?2026
• For a reaction: N 2+3 H 2 → 2 NH 3, the rate of reaction with respect to NH 3 is2026
• Half-life (t 1 / 2) of a first order reaction is 1386 s. The value of rate constant is:2026asked 3×
• The rate of a first order reaction is 5 · 6 × 10^-4 mol L^-1 s^-1, when the concentration of reactant is 0.2 mol L^-1. The rate…2026asked 3×
• The activation energy of a reaction can be determined from the slope of which of the following curves?2026
• The half-life periods of decomposition of NH 3 for different initial pressures are given below: The order of the reaction is:2026
• For the reaction 2A → 3B, the rate of reaction +(d[B])/(dt) is equal to:2026
• Assertion: The molecularity of the given reaction is 2 2 HI → H 2+I 2 Reason (R): Two molecules of the reactants are involved in…2026asked 3×
• Assertion: For complex reaction, order of reaction is given by the fast step. Reason (R): Order of reaction is determined…2026
• Assertion: For complex reaction, order of reaction is given by the slowest step. Reason (R): Order of a reaction is an…2026
• Assertion: For complex reaction, order of reaction is given by the slowest step. Reason (R): Order of reaction is not applicable…2026
• Assertion: Order of reaction is applicable to elementary as well as complex reactions. Reason ( R ): Order of a reaction is an…2026
• Assertion: Order of reaction is not applicable for elementary reaction but applicable for complex reaction. Reason (R): Order of…2026
• The concentration of the reactant is reduced from 0.6 mol L^-1 to 0.2 mol L^-1 in 5 minutes in a first order reaction. Calculate…2026asked 3×
• Reactions of which order will show the rate to be independent of the concentration of the reactant? Give one example of this…2026asked 3×
• For a reaction A+B → Products, the rate law is: Rate =k[ A][B]^3/2 Write the overall order of the reaction. Can this reaction be…2026asked 3×
• Define activation energy. 1 + 1 Write the unit of rate constant for (i) zero order reaction, (ii) second order reaction.2026
• Define Effective collision. 1 + 1 Write the unit of (i) second order reaction and (ii) zero order reaction2026
• Define Collision frequency. 1 + 1 Write the units of (i) first order reaction and (ii) zero order reaction2026
• Following reaction takes place in one step: 2 A+B → 2 C How will the rate of above reaction change if the volume of the reaction…2026asked 3×
• The half-life period of a radioactive element is 1.5 × 10^10 years. Calculate the time in which the activity of the element is…2026asked 3×
• For the first order thermal decomposition reaction, following data was obtained: C 2 H 5 Cl( g) → C 2 H 4( g)+HCl( g) Calculate…2026
• Define order of a reaction. The rate for the following reaction is given by: A+B → C Rate =k[A][B]^2 (i) How is the rate of…2026asked 3×
• The rate of the chemical reaction doubles when the temperature is raised from 298 K to 308 K. Calculate activation energy (E a)…2026
• The rate of a particular reaction quadruples when the temperature increases from 293 K to 313 K. Calculate the energy of…2026
• The rate of a particular reaction quadruples when the temperature increases from 300 K to 320 K. Calculate the energy of…2026
• Consider the decomposition of hydrogen peroxide (H 2 O 2) as per the equation given below: 2 H 2 O 2 [ Alkaline medium ]I^- 2 H 2…2026asked 3×
• The role of a catalyst is to change:2025asked 3×
• Which among the following is a false statement?2025asked 3×
• The number of molecules that react with each other in an elementary reaction is a measure of the:2025asked 3×
• The activation energy (E a) of a reaction can be determined from the slope of which of the following plots?2025
• Unit of rate constant 'k' for a second order reaction is:2025
• Which of the following is the slope of the first order reaction in the plot of ln [R] vs. time?2025
• Which of the following represents the fraction of molecules with energies equal to or greater than E a?2025asked 3×
• A plot between concentration of reactant [R] and time 't' is shown below. Which of the given order of reaction is indicated by…2025asked 3×
• In the Arrhenius equation k=Ae^-E a / RT, 'A' represents:2025
• The value of rate constant for a pseudo first order reaction:2025
• The unit of rate and rate constant are same for a:2025
• Assertion: In a first order reaction, if the concentration of the reactant is doubled, its half-life is also doubled. Reason (R):…2025asked 3×
• Assertion: Hydrolysis of an ester follows first order kinetics. Reason (R): The concentration of water does not get altered much…2025
• Assertion: Cooking time is reduced in pressure cooker. Reason (R): Boiling point of water inside the pressure cooker is lowered…2025
• Assertion: Order of the reaction can be zero or fractional. Reason (R): We cannot determine order from balanced chemical equation.2025
• Assertion: Molecularity of reaction is determined experimentally. Reason (R): Molecularity is applicable only for an elementary…2025
• Reactant 'A' underwent a decomposition reaction. The concentration of 'A' was measured periodically and recorded in the table…2025asked 2×
• The rate constant for a zero order reaction A → P is 0.0030 mol L^-1 s^-1. How long will it take for the initial concentration of…2025asked 3×
• Why is molecularity applicable only for elementary reactions and order is applicable for elementary as well as complex reactions?2025
• Define the following terms: 2 × 1 Pseudo first order reaction Half-life period of reaction (t 1 / 2)2025
• Observe the graph in the given figure and answer the following questions: Predict the order of reaction. What is the slope of the…2025asked 3×
• A reaction is of second order with respect to a reactant. How is the rate of reaction affected if the concentration of the…2025
• What is meant by the Rate law and Rate constant of a reaction. Identify the order of a reaction if the units of its Rate constant…2025
• State a condition under which a bimolecular reaction is kinetically first order reaction. Give an example. For which type of…2025asked 2×
• Write the rate law expression for the reaction 2 HI → H 2+I 2, if the order of the reaction is zero. What is the effect of…2025
• Define rate constant. Identify the reaction order which has a rate constant of 4 · 5 × 10^-5 L mol^-1 s^-1.2025
• Give any two differences between order and molecularity of a reaction. For a reaction X+Y → Z, in which both X and Y follow first…2025
• The reaction between A 2( g) and B 2( g) was carried out in a sealed isothermal container. The rate law for the reaction was…2025
• For the reaction A+B → Products, the following initial rates were obtained at various initial concentrations of reactants:…2025asked 3×
• The rate of a reaction: A+B → product is given below as a function of different initial concentrations of A and B. Calculate the…2025asked 3×
• The following data were obtained during the first order thermal decomposition of N 2 O 5( g) at constant volume: 2 N 2 O 5( g) →…2025asked 3×
• A certain reaction is 50% complete in 20 minutes at 300 K and the same reaction is 50% complete in 5 minutes at 350 K. Calculate…2025asked 2×
• The rate of a reaction quadruples when the temperature changes from 293 K to 313 K. Calculate the energy of activation of the…2025
• The rate of a chemical reaction is expressed either in terms of decrease in the concentration of reactants or increase in the…2025asked 3×
• (i) The initial concentration of N 2 O 5 in the first order reaction: N 2 O 5( g) → 2 NO 2( g)+1/2 O 2( g) was 1 · 2 × 10^-2 mol…2025asked 3×
• A zero-order reaction is one whose rate is independent of:2024
• For the reaction X+2 Y → P, the differential form equation of the rate law is:2024
• A reaction A 2+B 2 → 2 AB occurs by the following mechanism: Its order would be:2024
• In effective collisions the colliding molecules must have:2024
• The fraction of molecules having energy equal to or greater than activation energy is:2024
• The correct Mathematical expression of Arrhenius equation is2024
• The rate of a reaction increases sixteen times when the concentration of the reactant increases four times. The order of the…2024asked 2×
• In the Arrhenius equation, when log k is plotted against 1/T, a straight line is obtained whose:2024asked 3×
• In a given graph of zero order reaction, the slope and intercept are:2024asked 3×
• For a certain reaction R → products, a plot of log [R] vs. time gives a straight line with a slope of -1 · 25 s^-1. The order of…2024
• Half-life period of a first order reaction is 1386 seconds. The rate constant (k) of the reaction is:2024
• When a catalyst increases the rate of a chemical reaction, then the rate constant (k):2024
• The half life of a first order reaction with rate constant (k) of 3 min^-1 is:2024
• For a zero order reaction A → products, t 1 / 2 is:2024
• The addition of catalyst during a chemical reaction alters which of the following quantities of the reaction?2024
• When the initial concentration of a reactant is doubled in the reaction, the half life period remains same. The order of reaction…2024
• The rate of the reaction 2 A+B 2 → 2 AB is given by Rate =k[A]^2[ B 2]. The value of rate constant (k) can be increased by:2024
• For the reaction A+2 B → C+D. The order of the reaction is2024
• For the elementary reaction P → Q, the rate of disappearance of 'P' increases by a factor of 8 upon doubling the concentration of…2024
• Assertion: Order of reaction and molecularity are always same for complex reactions. Reason (R): Order is determined…2024
• Assertion: Rate of reaction increases with increase in temperature. Reason (R): Number of effective collisions increase with…2024
• Assertion: Rate of reaction decreases with increase in temperature. Reason (R): Number of effective collisions increases with…2024
• Define the following terms: Order of a reaction Activation energy 1 × 22024
• Define the following terms: Molecularity of reaction Complex reaction2024
• Define the following terms: Half life period (t 1 / 2) Effective collisions2024
• In a reaction, if the concentration of reactant ' X ' is tripled, the rate of reaction becomes twenty-seven times. What is the…2024asked 3×
• A first order reaction has a rate constant 1.25 × 10^-3 s^-1. How long will 5 g of this reactant take to reduce to 2.5 g? [ log…2024asked 3×
• Define molecularity of the reaction. State any one condition in which a bimolecular reaction may be kinetically of first order.2024
• For a chemical reaction R → P, the variation in the concentration [R] vs time t plot is given as: Predict the order of the…2024
• Show that in case of a first order reaction, the time taken for completion of 99% reaction is twice the time required for 90%…2024asked 2×
• A first order reaction takes 40 min for 75 % decomposition. Calculate rate constant. [Given: log 2=0.30, log 4=0.60 ]2024
• Write two differences between order of reaction and molecularity of reaction.2024
• The following initial rate data were obtained for the reaction: 2 NO( g)+Br 2( g) → 2 NOBr( g) What is the order with respect to…2024asked 3×
• A first-order reaction is 25% complete in 40 minutes. Calculate the value of rate constant. In what time will the reaction be 80%…2024asked 3×
• The rate constant of a reaction quadruples when the temperature changes from 300 K to 320 K. Calculate the activation energy for…2024asked 2×
• Show that the time required for 99.9 % completion in a first order reaction is 10 times of half-life (t 1 / 2) of the reaction […2024asked 3×
• The rate of a gaseous reaction triples when temperature is increased from 17^° C to 27^° C. Calculate the energy of activation…2024asked 3×
• The rate constant of a reaction quadruples when the temperature changes from 700 K to 720 K. Calculate the activation energy for…2024
• On dissolving ammonium chloride in water at room temperature, the solution feels cool to touch. Under which of the following…2023
• The half-life for a zero order reaction equals:2023
• For the reaction A+2 B → C+D, the rate law is given by r=k[A][B]^2, the concentration of A is kept constant while that of B is…2023
• For a zero order reaction of the type A → products, the rate equation may be expressed as:2023
• The slope in the plot of [R] vs. time for a zero order reaction is2023
• The slope in the plot of ln [R] vs. time for a first order reaction is 12023
• The slope in the plot of log ([R] 0)/([R]) vs. time for a first order reaction is2023
• A first order reaction takes 30 minutes for 50 % completion. The value of rate constant k would be:2023
• Which of the following is affected by catalyst?2023asked 3×
• The order of the reaction H 2( g)+Cl 2( g) h ν 2 HCl( g) is:2023asked 2×
• The rate of reaction A+B → Products, is given by the equation r=k[A] [B]. If B is taken in large excess, the order of reaction…2023
• The unit of the rate of reaction is the same as that of the rate constant for a:2023
• In a reaction, the initial concentration of the reactants increases four fold and the rate becomes sixteen times its initial…2023
• If the initial concentration is reduced to 1/4 th in a zero order reaction, then the time taken for half the reaction to complete:2023
• The number of molecules that react with each other in an elementary reaction is a measure of the:2023
• The half-life of a reaction is doubled when the initial concentration is doubled. The order of the reaction is:2023
• For a reaction 2 A → 3 B, rate of reaction -(d[A])/(dt) is equal to 12023
• For the reaction 3 A → 2 B, rate of reaction +(d[B])/(dt) is equal to2023asked 2×
• For the reaction 3 A → 2 B, rate of reaction -(d[A])/(dt) is equal to2023
• The following experimental rate data were obtained for a reaction carried out at 25 °C: A (g)+B (g) → C (g)+D (g) What are the…2023asked 3×
• Assertion: Order and molecularity of a reaction are always same. Reason (R): Complex reactions involve a sequence of elementary…2023asked 3×
• Assertion: Order of reaction is applicable to elementary as well as complex reactions. Reason (R): For a complex reaction…2023
• Assertion: For a zero order reaction the unit of rate constant and rate of reaction are same. Reason (R): Rate of reaction for…2023asked 4×
• Assertion: The half life of a reaction is the time in which the concentration of the reactant is reduced to one half of its…2023
• Assertion: The molecularity of the reaction H 2+Br 2 → 2 HBr appears to be 2. Reason (R): Two molecules of the reactants are…2023asked 3×
• The half-life of a first order reaction is 60 minutes. How long will it take to consume 90%of the reactant? [Given: log 2=0 ·…2023
• What happens to the rate constant k and activation energy E a as the temperature of a chemical reaction is increased? Justify.2023asked 3×
• A chemical reaction 2 N 2 O 5( g) → 4 NO 2( g)+O 2( g) in gas phase was carried out in a closed vessel. The concentration of NO 2…2023
• The conversion of molecule A to B followed second order kinetics. If concentration of A increased to three times, how will it…2023asked 3×
• The rate constant for the first order decomposition of N 2 O 5 is given by the following equation: log k=23 · 6-(2 × 10^4 K)/( T)…2023asked 3×
• The following data were obtained for the reaction: 2 NO 2( g)+F 2( g) → 2 NO 2 F( g) Determine the overall order of reaction.2023
• For the reaction 2 N 2 O 5( g) → 4 NO 2( g)+O 2( g) at 318 K calculate the rate of reaction if rate of disappearance of N 2 O 5(…2023asked 3×
• A first order reaction is 50%complete in 30 minutes at 300 K and in 10 minutes at 320 K. Calculate activation energy (E a) for…2023asked 3×
• The rate of a reaction doubles when temperature changes from 27°C to 37°C. Calculate energy of activation for the reaction.…2023asked 3×
• The following data were obtained during the first order thermal decomposition of C 2 H 5 Cl at a constant volume: C 2 H 5 Cl( g)…2023asked 3×
• The rate of reaction is concerned with decrease in concentration of reactants or increase in the concentration of products per…2023asked 3×
• Answer the following questions (Do any two): Identify the order of reaction from the following unit for its rate constant:…2022asked 3×
• Define rate of reaction. Write two factors that affect the rate of reaction.2022
• A reaction is second order in X and first order in Y. How is the rate affected when the concentrations of both X and Y are…2022
• In the given reaction N 2( g)+3 H 2( g) → 2 NH 3( g) the rate of formation of NH 3 is 3 · 6 × 10^-4 mol L^-1 s^-1. Calculate the…2022
• In a reaction 2 N 2 O 5( g) → 4 NO 2( g)+O 2( g), the concentration of N 2 O 5 decreases from 0.5 mol L^-1 to 0.4 mol L^-1 in 10…2022
• What do you mean by complex reactions? Can we determine order and molecularity of a complex reaction?2022
• A reaction is first order in X and second order in Y. (i) How is the rate affected on increasing the concentration of Y three…2022
• A first order reaction is 50% complete in 40 minutes. Calculate the time required for the completion of 90% of reaction. [Given:…2022asked 3×
• Observe the graph shown in figure and answer the following questions: What is the order of the reaction? What is the slope of the…2022asked 3×
• A first order reduction takes 30 minutes for 75% decomposition. Calculate t 1 / 2. Given: [ log 2=0 · 3, log 3=0 · 48, log 4=0 ·…2022asked 3×
• Read the passage given below and answer the questions that follow: The rate law for a chemical reaction relates the reaction rate…2022asked 3×
• Read the following passage and answer the questions that follow: The rate of reaction is concerned with decrease in concentration…2022asked 3×

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