For a first order reaction, the time required for completion of 90% reaction is ‘x’ times the half life of the reaction. The value of ‘x’ is (Given: In 10 = 2.303 and log 2 = 0.3010)
- 1.12
- 2.43
- 3.32
- 33.31
The Correct Option is C
Solution and Explanation
A → Products
For a first order reaction,
\(t_{1/2} = \frac{ln2}{k} = \frac{0.693 }{ k}\)
Time for \(90\% \) conversion,
\(t_{ 90\%} = \frac{1}{k} \;In \;\frac{100}{10 }= \frac{ln10}{k} = \frac{2.303}{k}\)
\(t_{90\%} = \frac{2.303}{0.693} \;t_{1/2} = 3.32 \;t_{1/2}\)
Top Questions on Order of Reaction
- A reaction is of second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reactant is (i) doubled, (ii) reduced to half?
- CBSE CLASS XII - 2025
- Chemistry
- Order of Reaction
- For a first-order reaction, the concentration of a reactant decreases from 0.8 M to 0.4 M in 20 minutes. What is the half-life of the reaction? (Use $\ln 2 = 0.693$)
- AP EAPCET - 2025
- Chemistry
- Order of Reaction
The following data were obtained for the reaction: \[ 2NO(g) + O_2(g) \rightarrow 2N_2O(g) \] at different concentrations:
The rate law of this reaction is:- KEAM - 2025
- Chemistry
- Order of Reaction
- For a first-order reaction, the slope of the graph between \(\log[A]\) vs time is equal to:
- MHT CET - 2025
- Chemistry
- Order of Reaction
- Which of the following plots gives a straight line for a zero-order reaction?
- MHT CET - 2025
- Chemistry
- Order of Reaction
Questions Asked in JEE Main exam
- The sum of all rational numbers in \( (2 + \sqrt{3})^8 \) is:
- JEE Main - 2025
- Binomial theorem
- The maximum covalency of a non-metallic group 15 element 'E' with the weakest E-E bond is:
- JEE Main - 2025
- Group 15 Elements
Let one focus of the hyperbola $ \frac{x^2}{a^2} - \frac{y^2}{b^2} = 1 $ be at $ (\sqrt{10}, 0) $, and the corresponding directrix be $ x = \frac{\sqrt{10}}{2} $. If $ e $ and $ l $ are the eccentricity and the latus rectum respectively, then $ 9(e^2 + l) $ is equal to:
- JEE Main - 2025
- Conic sections
The largest $ n \in \mathbb{N} $ such that $ 3^n $ divides 50! is:
- JEE Main - 2025
- Number Systems
- For an experimental expression \( y = \frac{32.3 \times 1125}{27.4} \), where all the digits are significant. Then to report the value of \( y \), we should write:
- JEE Main - 2025
- Significant figures
Concepts Used:
Order of Reaction
The Order of reaction refers to the relationship between the rate of a chemical reaction and the concentration of the species taking part in it. In order to obtain the reaction order, the rate equation of the reaction will given in the question.
Characteristics of the reaction order
- Reaction order represents the number of species whose concentration directly affects the rate of reaction.
- It can be obtained by adding all the exponents of the concentration terms in the rate expression.
- The order of reaction does not depend on the stoichiometric coefficients corresponding to each species in the balanced reaction.
- The reaction order of a chemical reaction is always defined with the help of reactant concentrations and not with product concentrations.
- Integer or a fraction form the value of the order of reaction will be there and it can be zero.