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Consider the following statements
(i) First order reaction completes in infinite time. This true and a basic of reaction kinetics
(ii) Average life is independent of concentration for first order reactions t = 1/λ
(iii) t75% = 1.5 t1/2 for zero order reaction as there is linear dependence
(iv) t75% = 2t1/2 for first order reaction as there is exponential dependence
Correct among the following are
  • a)
    (i),(iii) and (iv)
  • b)
    (ii),(iv)
  • c)
    (i),(ii)
  • d)
    All are correct
Correct answer is option 'D'. Can you explain this answer?
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Most Upvoted Answer
Consider the following statements(i) First order reaction completes in...
K. This statement is also true and is a fundamental concept in first order reactions.

Explanation:

(i) The statement is true because in a first order reaction, the rate of reaction is proportional to the concentration of the reactant. As the concentration decreases with time, the rate of reaction also decreases. However, it can never reach zero as there will always be some molecules left to react. Therefore, the reaction will continue indefinitely and complete in infinite time.

(ii) The statement is also true because the average life of a molecule is the time taken for half of the molecules to react. This is independent of the concentration as the rate of reaction is proportional to the concentration. Therefore, the time taken for half of the molecules to react will always be the same, regardless of the concentration. The formula for average life is t = 1/k, where k is the rate constant of the reaction.
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Read the passage given below and answer the following questions:The rate of a reaction, which may also be called its velocity or speed, can be defined with relation to the concentration of any of the reacting substances, or to that of any product of the reaction. If the species chosen is a reactant which has a concentration c at time t the rate is - dc/dt, while the rate with reference to a product having a concentration x at time t is dx/dt. Any concentration units may be used for expressing the rate; thus, if moles per liter are employed for concentration and seconds for the time, the units for the rate are moles litre–1sec–1. For gas reactions pressure units are sometimes used in place of concentrations, so that legitimate units for the rate would be (mm. Hg) sec–1 and atm. sec–1 The order of a reaction concerns the dependence of the rate upon the concentrations of reacting substances; thus, if the rate is found experimentally to be proportional to the ath power of the concentration of one of the reactants A, to the both power of the concentration of a second reactant B, and so forth, via., rate = k CAα CAβ the over-all order of the reaction is simply n = α + β + ----- (2) Such a reaction is said to be of the αth order with respect to the substance A, the βth order with respect to B.In the following questions, a statement of Assertion followed by a statement of Reason is given. Choose the correct answer out of the following choices on the basis of the above passage.Assertion: For a reaction: P + 2Q → Products, Rate = k [P]1/2[Q]1 so the order of reaction is 1.5Reason: Order of reaction is the sum of stoichiometric coefficients of the reactants.

Read the passage given below and answer the following questions:The rate of a reaction, which may also be called its velocity or speed, can be defined with relation to the concentration of any of the reacting substances, or to that of any product of the reaction. If the species chosen is a reactant which has a concentration c at time t the rate is - dc/dt, while the rate with reference to a product having a concentration x at time t is dx/dt. Any concentration units may be used for expressing the rate; thus, if moles per liter are employed for concentration and seconds for the time, the units for the rate are moles litre–1sec–1. For gas reactions pressure units are sometimes used in place of concentrations, so that legitimate units for the rate would be (mm. Hg) sec–1 and atm. sec–1 The order of a reaction concerns the dependence of the rate upon the concentrations of reacting substances; thus, if the rate is found experimentally to be proportional to the ath power of the concentration of one of the reactants A, to the both power of the concentration of a second reactant B, and so forth, via., rate = k CAα CAβ the over-all order of the reaction is simply n = α + β + ----- (2) Such a reaction is said to be of the αth order with respect to the substance A, the βth order with respect to B.In the following questions, a statement of Assertion followed by a statement of Reason is given. Choose the correct answer out of the following choices on the basis of the above passage.Assertion: Reactions can occur at different speeds.Reason: Rate of reaction is also called speed of reaction.

Consider the following statements(i) First order reaction completes in infinite time. This true and a basic of reaction kinetics(ii) Average life is independent of concentration for first order reactions t = 1/λ(iii) t75% = 1.5 t1/2 for zero order reaction as there is linear dependence(iv) t75% = 2t1/2 for first order reaction as there is exponential dependenceCorrect among the following area)(i),(iii) and (iv)b)(ii),(iv)c)(i),(ii)d)All are correctCorrect answer is option 'D'. Can you explain this answer?
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Consider the following statements(i) First order reaction completes in infinite time. This true and a basic of reaction kinetics(ii) Average life is independent of concentration for first order reactions t = 1/λ(iii) t75% = 1.5 t1/2 for zero order reaction as there is linear dependence(iv) t75% = 2t1/2 for first order reaction as there is exponential dependenceCorrect among the following area)(i),(iii) and (iv)b)(ii),(iv)c)(i),(ii)d)All are correctCorrect answer is option 'D'. Can you explain this answer? for Class 12 2024 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about Consider the following statements(i) First order reaction completes in infinite time. This true and a basic of reaction kinetics(ii) Average life is independent of concentration for first order reactions t = 1/λ(iii) t75% = 1.5 t1/2 for zero order reaction as there is linear dependence(iv) t75% = 2t1/2 for first order reaction as there is exponential dependenceCorrect among the following area)(i),(iii) and (iv)b)(ii),(iv)c)(i),(ii)d)All are correctCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Class 12 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider the following statements(i) First order reaction completes in infinite time. This true and a basic of reaction kinetics(ii) Average life is independent of concentration for first order reactions t = 1/λ(iii) t75% = 1.5 t1/2 for zero order reaction as there is linear dependence(iv) t75% = 2t1/2 for first order reaction as there is exponential dependenceCorrect among the following area)(i),(iii) and (iv)b)(ii),(iv)c)(i),(ii)d)All are correctCorrect answer is option 'D'. Can you explain this answer?.
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