मराठी

Which of the following statement is true? (a) molecularity of reaction can be zero or a fraction. (b) molecularity has no meaning for complex reactions.

Advertisements
Advertisements

प्रश्न

Which of the following statement is true?

पर्याय

  • Molecularity of reaction can be zero or a fraction.

  • Molecularity has no meaning for complex reactions.

  • Molecularity of a reaction is an experimental quantity.

  • Reactions with the molecularity three are very rare but are fast.

MCQ
Advertisements

उत्तर

Molecularity has no meaning for complex reactions.

Explanation:

The order of a reaction is an experimental quantity. It can be zero and even a fraction, but molecularity cannot be zero or a non-integer. Order is applicable to elementary as well as complex reactions, whereas molecularity is applicable only for elementary reactions. For complex reaction, molecularity has no meaning.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
2023-2024 (March) Board Sample Paper

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

For a reaction: 

Rate = k

(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 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?


Define the following term:

Pseudo first-order reaction


Why is the probability of reaction with molecularity higher than three very rare?


Assertion: Order of the reaction can be zero or fractional.

Reason: We cannot determine order from balanced chemical equation.


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 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


Read the following passage and answer the questions that follow:

The rate of reaction is concerned with decrease in the concentration of reactants or increase in the concentration of products per unit of time. It can be expressed as instantaneous rate at a particular instant of time and average rate over a large interval of time. A number of factors such as temperature, concentration of reactants, catalyst affect the rate of reaction. Mathematical representation of rate of a reaction is given by rate law:

Rate = k[A]x [B]y

x and y indicate how sensitive the rate is to change in concentration of A and B. Sum of x + y gives the overall order of a reaction.
When a sequence of elementary reactions gives us the products, the reaction is called complex reaction. Molecularity and order of an elementary reaction are same. Zero-order reactions are relatively uncommon but they occur under special conditions. All natural and artificial radioactive decay of unstable nuclei takes place by first-order kinetics.

  1. What is the effect of temperature on the rate constant of a reason?    [1]
  2. For a reaction \[\ce{A + B → Product}\], the rate law is given by, Rate = k[A]2 [B]1/2. What is the order of the reaction?    [1]
  3. How order and molecularity are different for complex reactions?    [1]
  4. A first-order reaction has a rate constant 2 × 10–3 s–1. How long will 6 g of this reactant take to reduce to 2 g?    [2]
    OR
    The half-life for radioactive decay of 14C is 6930 years. An archaeological artifact containing wood had only 75% of the 14C found in a living tree. Find the age of the sample.
    [log 4 = 0.6021, log 3 = 0.4771, log 2 = 0.3010, log 10 = 1]    [2]

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)


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×