Rate law for the reaction A+2B⟶C is found to be Rate = k [A][B]. Concentration of reactant ‘B’ is doubled, keeping the concentration of ‘A’ constant, the value of rate constant will be ______. - Chemistry

Advertisements
Advertisements
MCQ
Fill in the Blanks

Rate law for the reaction \[\ce{A + 2B -> C}\] is found to be Rate = k [A][B]. Concentration of reactant ‘B’ is doubled, keeping the concentration of ‘A’ constant, the value of rate constant will be ______.

Options

  • the same

  • doubled

  • quadrupled

  • halved

Advertisements

Solution

Rate law for the reaction \[\ce{A + 2B -> C}\] is found to be Rate = k [A][B]. Concentration of reactant ‘B’ is doubled, keeping the concentration of ‘A’ constant, the value of rate constant will be doubled.

Explanation:

The rate concentration of a reaction does not depend upon concentrations of the reactions. Hence, it will remain the same. Even if the equation shows the double concentration level even the rate concentration doubles so it's the same throughout.

Following with the equation \[\ce{A + 2B -> C}\] 

If rate considered as (1) Rate1 = k[A][B]

If rate considered as 2

Then, Rate1 = k[A][2B]

Rate2 = 2Rate1 

  Is there an error in this question or solution?
Chapter 4: Chemical Kinetics - Exercises [Page 51]

APPEARS IN

NCERT Exemplar Chemistry Class 12
Chapter 4 Chemical Kinetics
Exercises | Q I. 14. | Page 51

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Define "zero order reaction".


In a first order reaction x → y, 40% of the given sample of compound remains unreacted in 45 minutes. Calculate rate constant of the reaction.


A → B is a first order reaction with rate 6.6 × 10-5m-s-1. When [A] is 0.6m, rate constant of the reaction is

  • 1.1 × 10-5s-1
  • 1.1 × 10-4s-1
  • 9 × 10-5s-1
  • 9 × 10-4s-1

A reaction is second order in A and first order in B.

(i) Write the differential rate equation.

(ii) How is the rate affected on increasing the concentration of A three times?

(iii) How is the rate affected when the concentrations of both A and B are doubled?

 


What is pseudo first order reaction? Give one· example of it.


Write molecularity of the following reaction:

2NO(g)+O2(g)→2NO2(g)


For a reaction: 

Rate = k

(i) Write the order and molecularity of this reaction.

(ii) Write the unit of k.


Write two factors that affect the rate of reaction.


For a reaction A + B ⟶ P, the rate is given by

Rate = k [A] [B]2

How is the rate of reaction affected if the concentration of B is doubled?


For a reaction A + B ⟶ P, the rate is given by

Rate = k [A] [B]2

What is the overall order of reaction if A is present in large excess?


For a reaction : 

(i) Write the order and molecularity of this reaction.

(ii) Write the unit of k.


For the hydrolysis of methyl acetate in aqueous solution, the following results were obtained :

t/s 0 30 60
[CH3COOCH3] / mol L–1 0.60 0.30 0.15

(i) Show that it follows pseudo first order reaction, as the concentration of water remains constant.

(ii) Calculate the average rate of reaction between the time interval 30 to 60 seconds.

(Given log 2 = 0.3010, log 4 = 0.6021)


The following data were obtained during the first order thermal decomposition of SO2Cl2 at a constant volume :

SO2Cl2 (g) → SO2 (g) + Cl2 (g)

Experiment Time/s–1 Total pressure/atm
1 0 0.4
2 100 0.7

Calculate the rate constant.

(Given : log 4 = 0.6021, log 2 = 0.3010)


For a reaction, A + B → Product; the rate law is given by, `r = k[A]^(1/2)[B]^2` . What is the order of the reaction?


The conversion of molecules X to Y follows second order kinetics. If concentration of X is increased to three times how will it affect the rate of formation of Y?


A first order reaction has a rate constant 1.15 10−3 s−1. How long will 5 g of this reactant take to reduce to 3 g?


Mention the factors that affect the rate of a chemical reaction.


How does calcination differ from roasting?


Write resonating structures of ozone.


The decomposition of N2O5(g) at 320K according to the following equation follows first order reaction:

`N_2O_(5(g))->2NO_(2(g))+1/2O_(2(g))`

The initial concentration of N2O5(g) is 1.24 x 10-2 mol. L-1 and after 60 minutes 0.20x10-2 molL-1. Calculate the rate constant of the reaction at 320K.


Write the principle behind the following methods of refining:

Hydraulic washing


Define the following terms:

Half-life period of reaction (t1/2).


Consider a first order gas phase decomposition reaction given below :
\[\ce{A(g) -> B(g) + C(g)}\]
The initial pressure of the system before decomposition of A was pi. After lapse of time ‘t’, total pressure of the system increased by x units and became ‘pt’ The rate constant k for the reaction is given as ______.


Why can we not determine the order of a reaction by taking into consideration the balanced chemical equation?


Assertion: Order and molecularity are same.

Reason: Order is determined experimentally and molecularity is the sum of the stoichiometric coefficient of rate determining elementary step.


Assertion: The enthalpy of reaction remains constant in the presence of a catalyst.

Reason: A catalyst participating in the reaction, forms different activated complex and lowers down the activation energy but the difference in energy of reactant and product remains the same.


Use Molecular Orbital theory to determine the bond order in each of species, [He2j+ and [He2]2+?


A catalyst in a reaction changes which of the following?


In the presence of a catalyst, the heat evolved or absorbed during the reaction.


For a reaction R → p the concentration of reactant change from 0.03 m to 0.02 m in minute, calculate the average rate of the reaction using the unit of second.


For a reaction \[\ce{Cl2l(g) + 2No(g) -> 2NaCl(g)}\] the rate law is expressed as rate= K[Cl2] [No]2 what is the order of the reaction?


The rate constant for the reaction \[\ce{2H2O5 -> 4NO2 + O2}\] is 30 × 10–5 sec–1. if the rate is 204 × 10–5 mol L1 S1, then the concentration of N2O5 (in mol1) is-


For a first order A → B, the reaction rate at reactant concentration of 0.01 m is found to be 2.0 × 10–5. The half-life period of reaction.


The rate of a chemical reaction double for every 10° rise in temperature. If the temperature is raised. by 50°C, the rate of relation by about:-


The half-life period 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 mol–1 to 0.04 mg L–1 is


At concentration of 0.1 and 0.2 mol L–1 the rates of deem position of a compound were found to be 0.18 and 0.72 mol L–1 m–1. What is the order of the reaction?


The number of molecules of the reactants taking part in a single step of the reaction is indicative of ______.


For the reaction, \[\ce{A +2B → AB2}\], the order w.r.t. reactant A is 2 and w.r.t. reactant B. What will be change in rate of reaction if the concentration of A is doubled and B is halved?


Identify the order of reaction from the following unit for its rate constant: L mol–1s–1


On heating compound (A) gives a gas (B) which is constituent of air. The gas when treated with H2 in the presence of catalyst gives another gas (C) which is basic in nature, (A) should not be ______.


The following data was obtained for chemical reaction given below at 975 K.

\[\ce{2NO(g) + 2H2(g) -> N2(g) + 2H2O(g)}\]

  [NO] [H2] Rate
  Mol L-1 Mol L-1 Mol L-1 s-1
(1) 8 × 10-5 8 × 10-5 7 × 10-9
(2) 24 × 10-5 8 × 10-5 2.1 × 10-8
(3) 24 × 10-5 32 × 10-5 8.4 × 10-8

The order of the reaction with respect to NO is ______. (Integer answer)


A drop of solution (volume 0.05 ml) contains 3.0 × 10-6 mole of H+. If the rate constant of disappearance of H+ is 1.0 × 107 mole l-1s-1. It would take for H+ in drop to disappear in ______ × 10-9s.


For a chemical reaction starting with some initial concentration of reactant At as a function of time (t) is given by the equation,

`1/("A"_"t"^4) = 2 + 1.5 xx 10^-3` t

The rate of disappearance of [A] is ____ × 10-2 M/sec when [A] = 2 M.

[Given: [At] in M and t in sec.]
[Express your answer in terms of 10-2 M /s]
[Round off your answer if required]


A flask contains a mixture of compounds A and B. Both compounds decompose by first-order kinetics. The half-lives for A and B are 300 s and 180 s, respectively. If the concentrations of A and B are equal initially, the time required for the concentration of A to be four times that of B (in s) is ______. (Use ln 2 = 0.693)


Which of the following statement is true?


Share
Notifications



      Forgot password?
Use app×