JEE Main · Chemistry · Thermodynamics (Chemistry)
Gibbs Free Energy: JEE Main previous year questions
29 questions in the 108 JEE Main shifts Lumi analysed, in 6 of 8 years. Pattern: Asked most years. 12 came in 2024–26. Here is how it is asked and which ideas come back.
- Questions
- 29
- in 27 of 108 shifts
- Years asked
- 6/8
- last asked 2026
- Weighted estimate
- 0.3
- model; history: 0.2 a shift on average, typically 0.0–0.3
Key findings
- 01
Asked in 6 of 8 years with analysed shifts and in 27 of 108 shifts: 29 questions, #116 of 196 topics.
- 02
59% of its questions since 2020 tested an idea no earlier year had asked; 7 repeated an idea from the year before.
- 03
The most repeated idea is Gibbs Energy and Equil, asked 10 times in 10 shifts (2021, 2022, 2023, 2024, 2026), most often as “standard free energy from dissociation”.
- 04
JEE Main has asked 15 of the 56 ideas in this topic; 30 have never been asked, directly or inside another question.
- 05
Mostly asked as numerical value (66%); 66% need a numerical answer, 28% are easy and 14% hard.
- 06
The skill tested most is calculation (52%), then data or graph (17%).
Questions a shift, year by year
Out of the 25 Chemistry questions in a shift. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift.
Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 7 in 24 shifts · 2022: 6 in 24 shifts · 2023: 4 in 12 shifts · 2024: 5 in 18 shifts · 2025: 2 in 8 shifts · 2026: 5 in 9 shifts.
- Up to 2023
- 0.1
- a shift, of 25
- Since 2024
- 0.3
- 0.2
- Usual gap
- 1.0 yrs
- between years asking it
- Shifts with it
- 27/108
- 25% of analysed shifts
How it is asked
Difficulty, format and skill
Across all 29 questions on Gibbs Free Energy since 2017.
Difficulty
QUESTIONS- Easy8 · 28%
- Medium17 · 59%
- Hard4 · 14%
Format
SHARE- Numerical value · 19 Q66%
- Diagram based · 4 Q14%
- Single correct · 3 Q10%
- Two statements · 1 Q3%
- Other · 1 Q3%
- Match the list · 1 Q3%
Skill tested
SHARE- Calculation · 15 Q52%
- Data or graph · 5 Q17%
- Conceptual · 5 Q17%
- Multi-step · 4 Q14%
Repeats
New idea, or one asked before?
Each column is a year. Blue questions tested an idea no earlier year had asked; navy ones went back to an idea from an earlier year. 2017 is the first year, so everything in it counts as new. Heights are question counts, and Lumi analysed 1 to 24 shifts a year, so compare the split inside a column rather than heights across years.
- Idea asked for the first time
- Idea asked in an earlier year
Coverage of the topic
JEE Main has asked 15 of the 56 ideas in this topic. 30 have never been asked yet.
- Asked directly15 · 27%
- Touched inside another question11 · 20%
- Never asked30 · 54%
Ideas come from Lumi’s JEE syllabus map. A never-asked idea is not a safe skip: across all of JEE Main, 22% of questions since 2024 tested an idea no earlier year had asked.
Drill down
Chapter, idea, question
Every idea JEE Main tested in this topic, with its eight years. Open one to read the questions.
9 ideas inside
Squares are the 8 years with analysed shifts, 2017 to 2026. A number is the questions that year when there is more than one; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. Share is of the level above.
Ideas
Every idea inside this topic
15 different ideas were tested; 5 came more than once.
standard free energy from dissociation
Numerical value · 10 shifts · 9 numericalminimum temperature for spontaneity
Numerical value · 3 shifts · 3 numericalgraph interpretation of thermodynamic quantities
Diagram based · 2 shiftstrue statement selection on gibbs energy
Match the list · 2 shiftsfree energy change from electrode potentials
Numerical value · 2 shifts · 2 numericalvolume change from fuel cell work
Numerical value · 1 shift · 1 numericaldelta g from tabulated data
Single correct · 1 shifttransition temperature from delta g expression
Numerical value · 1 shift · 1 numericalidentify extensive property that changes
Diagram based · 1 shiftboiling temperature from enthalpy and entropy
Numerical value · 1 shift · 1 numericalstatement i/ii on ellingham diagram
Two statements · 1 shiftreduction feasibility from ellingham diagram
Diagram based · 1 shiftcount correct statements on gibbs energy graph
Numerical value · 1 shift · 1 numericaldelta g from equilibrium constant
Numerical value · 1 shift · 1 numericalinterpret features of ellingham diagram
Diagram based · 1 shift
| Idea | Years asked | Times | Shifts | Format | Numerical |
|---|---|---|---|---|---|
| Gibbs Energy and Equilstandard free energy from dissociation | 10 | 10 | Numerical valueCalculation | 9 | |
| Temperature Dependenceminimum temperature for spontaneity | 3 | 3 | Numerical valueCalculation | 3 | |
| Gibbs Energy vs Temperature Graphgraph interpretation of thermodynamic quantities | 2 | 2 | Diagram basedData or graph | – | |
| Spontaneity Criteriatrue statement selection on gibbs energy | 2 | 2 | Match the listConceptual | – | |
| Standard Gibbs Energy and Standard Cell Potentialfree energy change from electrode potentials | 2 | 2 | Numerical valueCalculation | 2 | |
| Gibbs Energy and Cell Potentialvolume change from fuel cell work | 1 | 1 | Numerical valueMulti-step | 1 | |
| Gibbs Energy Definitiondelta g from tabulated data | 1 | 1 | Single correctCalculation | – | |
| Gibbs Energy in Phase Equilibriumtransition temperature from delta g expression | 1 | 1 | Numerical valueCalculation | 1 | |
| Extensive Nature of Gibbs Energyidentify extensive property that changes | 1 | 1 | Diagram basedConceptual | – | |
| Gibbs Energy at Phase Transitionsboiling temperature from enthalpy and entropy | 1 | 1 | Numerical valueCalculation | 1 | |
| Ellingham Diagram Basicsstatement i/ii on ellingham diagram | 1 | 1 | Two statementsConceptual | – | |
| Ellingham Diagram Reduction Feasibilityreduction feasibility from ellingham diagram | 1 | 1 | Diagram basedData or graph | – | |
| Gibbs Energy vs Extent of Reaction Curvecount correct statements on gibbs energy graph | 1 | 1 | Numerical valueData or graph | 1 | |
| Delta G vs Delta G-degree at Equilibriumdelta g from equilibrium constant | 1 | 1 | Numerical valueCalculation | 1 | |
| Ellingham Diagram Phase Changesinterpret features of ellingham diagram | 1 | 1 | Diagram basedData or graph | – |
Times and shifts count every analysed shift. Across JEE Main, 78% of questions since 2024 went back to an idea an earlier year had asked; the rest were new. All repeated ideas
Every question
Gibbs Free Energy questions, year by year
The opening words of each question as it appeared in the official paper, with the idea it tested. Open one for its options and the official answer.
JEE Main 20265 questions in 5 shifts
- 2 Apr, Shift 1Q75At the transition temperature , and where A and B are two states of…
Idea: Gibbs Energy in Phase Equilibrium
New ideaMediumNumerical value - 2 Apr, Shift 2Q73Consider the following two half-cell reactions along with the standard reduction potential given:…
Idea: Gibbs Energy and Cell Potential
New ideaHardNumerical value - 4 Apr, Shift 2Q72For the following reaction at 50 C and at 2 atm pressure, …
Idea: Gibbs Energy and Equil
HardNumerical value - 5 Apr, Shift 2Q54Consider the following data for the reaction at 600 K. The (in kJ…
Idea: Gibbs Energy Definition
New ideaMediumSingle correct - 6 Apr, Shift 1Q75Consider the reaction at 300 K. If and K are 28.40 kJ mol and …
Idea: Gibbs Energy and Equil
MediumNumerical value
JEE Main 20252 questions in 2 shifts
- 2 Apr, Shift 2Q54Which of the following graphs correctly represents the variation of thermodynamic properties of Haber's process ?
Idea: Gibbs Energy vs Temperature Graph
HardDiagram based · figure - 3 Apr, Shift 1Q53Which of the following properties will change when system containing solution 1 will become solution 2? Solution 1: 10 mol of solute x +…
Idea: Extensive Nature of Gibbs Energy
New ideaMediumDiagram based · figure
JEE Main 20245 questions in 5 shifts
- 6 Apr, Shift 2Q83For the reaction at 298 K, , kJ mol and kJ mol K. The…
Idea: Temperature Dependence
EasyNumerical value - 9 Apr, Shift 2Q83When kJ/mol and , then the temperature of vapour, at one atmosphere…
Idea: Gibbs Energy at Phase Transitions
New ideaEasyNumerical value - 1 Feb, Shift 2Q82For a certain reaction at 300K, K = 10, then for the same reaction is ________ kJ mol. (Given…
Idea: Gibbs Energy and Equil
Asked the year beforeEasyNumerical value - 29 Jan, Shift 1Q62Which of the following is not correct?
Idea: Spontaneity Criteria
EasySingle correct - 31 Jan, Shift 1Q84Consider the following reaction at 298 K. .…
Idea: Gibbs Energy and Equil
Asked the year beforeEasyNumerical value
JEE Main 20234 questions in 3 shifts
- 6 Apr, Shift 1Q84The value of log K for the reaction at 298 K is ________. (Nearest integer) Given:…
Idea: Gibbs Energy and Equil
Asked the year beforeMediumNumerical value - 6 Apr, Shift 1Q86Consider the graph of Gibbs free energy G vs Extent of reaction. The number of statement/s from the following which are true with respect…
Idea: Gibbs Energy vs Extent of Reaction Curve
New ideaMediumNumerical value · figure - 10 Apr, Shift 2Q65Gibbs energy vs T plot for the formation of oxides is given below. For the given diagram, the correct statement is -
Idea: Ellingham Diagram Reduction Feasibility
New ideaMediumDiagram based · figure - 13 Apr, Shift 2Q65Given below are two statements related to Ellingham diagram: Statement I : Ellingham diagrams can be constructed for formation of oxides,…
Idea: Ellingham Diagram Basics
New ideaMediumTwo statements
JEE Main 20226 questions in 5 shifts
- 30 Jul, Shift 2Q33Which of the following is the plot of Gibb's free energy (G) vs temperature (T), at constant pressure, for a pure substance?
Idea: Gibbs Energy vs Temperature Graph
New ideaMediumOther · figure - 24 Jun, Shift 1Q82At 300 K, ozone is fifty percent dissociated. The standard free energy change at this…
Idea: Gibbs Energy and Equil
Asked the year beforeMediumNumerical value - 25 Jun, Shift 1Q84The standard entropy change for the reaction is…
Idea: Gibbs Energy and Equil
Asked the year beforeEasyNumerical value - 26 Jun, Shift 2Q8640% of HI undergoes decompostion to and at 300 K. for this decompostion reaction at one…
Idea: Gibbs Energy and Equil
Asked the year beforeMediumNumerical value - 26 Jun, Shift 2Q87(0.001M) (0.01M) + The Gibbs free energy change for…
Idea: Standard Gibbs Energy and Standard Cell Potential
Asked the year beforeMediumNumerical value - 27 Jun, Shift 1Q63Match List - I with List - II. List - I (A) Spontaneous process (B) Process with P = 0, T = 0 (C)…
Idea: Spontaneity Criteria
New ideaEasyMatch the list
JEE Main 20217 questions in 7 shifts
- 27 Aug, Shift 2Q55Data given for the following reaction is as follows : Table…
Idea: Temperature Dependence
New ideaMediumNumerical value · figure - 31 Aug, Shift 2Q31The incorrect expression among the following is :
Idea: Gibbs Energy and Equil
New ideaMediumSingle correct - 24 Feb, Shift 1Q54For the reaction , the value of the equilibrium constant at 300 K and 1 atm is equal to 100.0. The…
Idea: Delta G vs Delta G-degree at Equilibrium
New ideaMediumNumerical value - 24 Feb, Shift 2Q53Assuming ideal behaviour, the magnitude of log K for the following reaction at C is . The value of is…
Idea: Gibbs Energy and Equil
New ideaMediumNumerical value - 26 Feb, Shift 1Q53For a chemical reaction ( kJ mol) the entropy change…
Idea: Temperature Dependence
New ideaEasyNumerical value - 17 Mar, Shift 1Q34The point of intersection and sudden increase in the slope, in the diagram given below, respectively, indicates :
Idea: Ellingham Diagram Phase Changes
New ideaMediumDiagram based · figure - 18 Mar, Shift 1Q56For the reaction the magnitude of the standard molar free energy…
Idea: Standard Gibbs Energy and Standard Cell Potential
New ideaHardNumerical value
Questions from the official JEE Main Paper 1 shifts published by NTA (CBSE for 2017). Questions NTA dropped are left out. Topic and idea tags, counts and notes are Lumi’s.