Important Chemical Kinetics Graphs for Class 12, JEE & NEET
Revise the most important Chemical Kinetics graphs in one place: reaction-order plots, rate equations, Arrhenius plot, activation energy and exothermic/endothermic energy profiles.
Graph-based questions in Chemical Kinetics test whether you can connect an equation with the shape, slope and intercept of a plot. For Class 12 boards, JEE and NEET, the most useful graphs to revise are those related to zero-, first- and second-order reactions, the Arrhenius equation, activation energy and reaction-energy profiles.
This visual revision page combines the original Chemca graph sheets with concise explanations, equations and exam-focused interpretation so that you can revise the chapter quickly before a test.
Chemical Kinetics Graphs for Order of Reaction
The integrated rate equation tells you which quantity should give a straight line when plotted against time. This is one of the fastest ways to identify the order of a reaction from experimental data.
[A] vs t is linear. The slope is −k.
ln[A] vs t is linear. The slope is −k.
1/[A] vs t is linear. The slope is +k.
Match the integrated rate equation with the straight-line form before reading the slope or intercept.
Arrhenius Equation and Temperature Dependence of Rate Constant
The Arrhenius equation explains why the rate constant generally increases with temperature. Its logarithmic form converts the temperature dependence into a straight-line relationship.
A plot of ln k versus 1/T is linear with slope −Ea/R and intercept ln A.
Activation Energy, Exothermic and Endothermic Reaction Graphs
Energy-profile diagrams show the relative energies of reactants, products and the transition-state region. They help you identify activation energy (Ea) and the sign of the reaction enthalpy change.
| What to identify | Graph interpretation | Exam reminder |
|---|---|---|
| Activation energy | Energy gap from reactants to the activated/transition-state level. | A catalyst lowers activation energy; it does not change the overall ฮH. |
| Exothermic reaction | Products lie at a lower energy level than reactants. | ฮH is negative. |
| Endothermic reaction | Products lie at a higher energy level than reactants. | ฮH is positive. |
All Important Chemical Kinetics Graphs — One-Page Revision
Use this combined graph sheet as a final revision resource after you have understood the equations and graph interpretation. For best retention, try to redraw each graph from memory and write its slope, intercept and related equation beside it.
How to Revise Chemical Kinetics Graphs for Exams
| Step | What to do | Why it helps |
|---|---|---|
| 1 | Write the integrated rate equation. | Prevents confusion between [A], ln[A] and 1/[A] plots. |
| 2 | Convert it mentally to y = mx + c. | Makes slope and intercept identification immediate. |
| 3 | Redraw the graph without looking. | Builds visual recall for MCQs and assertion-reason questions. |
| 4 | Practice numerical questions using slope data. | Connects the graph with the rate constant and activation energy. |
Chemical Kinetics Graphs — Quick FAQ
Which graph is linear for a zero-order reaction?
[A] versus time is linear for a zero-order reaction, with slope −k.
Which graph is linear for a first-order reaction?
ln[A] versus time is linear for a first-order reaction, with slope −k.
Which graph is linear for a second-order reaction?
1/[A] versus time is linear for a second-order reaction, with slope +k.
What is the slope of the Arrhenius plot of ln k versus 1/T?
The slope is −Ea/R.
Does a catalyst change the enthalpy change of a reaction?
No. A catalyst provides an alternative pathway with lower activation energy, but the overall ฮH remains unchanged.
For concept videos and problem-solving sessions, visit Chemca video lectures.
