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
The cycloalkene (X) on bromination consumes one mole of bromine per mole of (X) and gives the product (Y) in which C : Br ratio is \(3:1\). The percentage of bromine in the product (Y) is _________ % (Nearest integer).
Given:
\[ \text{H} = 1,\quad \text{C} = 12,\quad \text{O} = 16,\quad \text{Br} = 80 \]- JEE Main - 2026
- Chemistry
- 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 ratio of time required is $ \frac{t_1}{t_2} $, if $ t_1 $ is the time consumed when reactant reaches $ \frac{1}{4} $ of initial concentration and $ t_2 $ is the time when it reaches $ \frac{1}{8} $ of initial concentration.
- JEE Main - 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 moment of inertia of a square loop made of four uniform solid cylinders, each having radius R and length L (\(R \le L\)) about an axis passing through the mid points of opposite sides, is (Take the mass of the entire loop as M) :
- JEE Main - 2026
- Kinematics
Which of the following best represents the temperature versus heat supplied graph for water, in the range of \(-20^\circ\text{C}\) to \(120^\circ\text{C}\)?
- JEE Main - 2026
- Thermodynamics
- When a part of a straight capillary tube is placed vertically in a liquid, the liquid rises upto certain height \( h \). If the inner radius of the capillary tube, density of the liquid and surface tension of the liquid decrease by \(1%\) each, then the height of the liquid in the tube will change by ________ %.
- JEE Main - 2026
- thermal properties of matter
- A gas of certain mass filled in a closed cylinder at a pressure of $3.23\,\text{kPa}$ has temperature $50^\circ$C. The gas is now heated to double its temperature. The modified pressure is ___ Pa.
- JEE Main - 2026
- Thermodynamics
- Let the circle \(x^2+y^2=4\) intersect the \(x\)-axis at points \(A(a,0)\) and \(B(b,0)\). Let \(P(2\cos\alpha,2\sin\alpha)\), \(0<\alpha<\frac{\pi}{2}\), and \(Q(2\cos\beta,2\sin\beta)\) be two points on the circle such that \((\alpha-\beta)=\frac{\pi}{2}\). Then the point of intersection of lines \(AQ\) and \(BP\) lies on:
- JEE Main - 2026
- Circles
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.