Chemistry question insights
What 11 years of ICSE Class 10 Chemistry papers actually asked — by chapter, question length, type, difficulty and diagrams. Every figure is computed from the 869 questions in this bank.
These are descriptive statistics of past papers, not predictions. A chapter appearing often historically does not guarantee it will appear again.
Which chapters carry the most weight
A prominence index combining how many papers a chapter appeared in and its share of total marks.
Chapter prominence index (0–100)
- Organic Chemistry100/100Appeared in 100% of papers (11/11) · 19.0% of all marks (190) · 153 Qs
- Electrolysis85/100Appeared in 100% of papers (11/11) · 11.8% of all marks (118) · 107 Qs
- Mole Concept and Stoichiometry78/100Appeared in 91% of papers (10/11) · 11.0% of all marks (110) · 79 Qs
- Periodic Table, Periodic Properties and Variations of Properties75/100Appeared in 91% of papers (10/11) · 9.5% of all marks (95) · 94 Qs
- Acids, Bases and Salts72/100Appeared in 100% of papers (11/11) · 5.7% of all marks (57) · 51 Qs
- Metallurgy71/100Appeared in 91% of papers (10/11) · 8.0% of all marks (80) · 74 Qs
- Analytical Chemistry: Uses of Ammonium Hydroxide and Sodium Hydroxide71/100Appeared in 100% of papers (11/11) · 5.4% of all marks (54) · 52 Qs
- Sulphuric Acid70/100Appeared in 91% of papers (10/11) · 7.2% of all marks (72) · 63 Qs
- Chemical Bonding69/100Appeared in 91% of papers (10/11) · 6.7% of all marks (67) · 53 Qs
- Study of Compounds – Nitric Acid63/100Appeared in 91% of papers (10/11) · 4.1% of all marks (41) · 41 Qs
- Study of Compounds – Ammonia60/100Appeared in 82% of papers (9/11) · 5.4% of all marks (54) · 46 Qs
- Practical Work57/100Appeared in 82% of papers (9/11) · 3.9% of all marks (39) · 34 Qs
Index = 60% appearance frequency + 40% marks share, across all available papers. Historical, not predictive.
Organic Chemistry leads: it appears in 100% of papers (11 of 11) and carries 19.0% of all marks (190) across 153 questions.
Most questions asked
Share of all questions, by chapter.
- Organic Chemistry18%153 Qs
- Electrolysis12%107 Qs
- Periodic Table, Periodic Properties and Variations of Properties11%94 Qs
- Mole Concept and Stoichiometry9.1%79 Qs
- Metallurgy8.5%74 Qs
- Sulphuric Acid7.2%63 Qs
- Chemical Bonding6.1%53 Qs
- Analytical Chemistry: Uses of Ammonium Hydroxide and Sodium Hydroxide6.0%52 Qs
- Acids, Bases and Salts5.9%51 Qs
- Study of Compounds – Ammonia5.3%46 Qs
Percentages are of the full 869-question bank.
Most marks asked
Share of total marks, by chapter.
- Organic Chemistry19%190 marks
- Electrolysis12%118 marks
- Mole Concept and Stoichiometry11%110 marks
- Periodic Table, Periodic Properties and Variations of Properties9.5%95 marks
- Metallurgy8.0%80 marks
- Sulphuric Acid7.2%72 marks
- Chemical Bonding6.7%67 marks
- Acids, Bases and Salts5.7%57 marks
- Analytical Chemistry: Uses of Ammonium Hydroxide and Sodium Hydroxide5.4%54 marks
- Study of Compounds – Ammonia5.4%54 marks
Percentages are of the 1,000 marks across all papers.
Short vs long questions
Short = less than 2 marks (recall / one-liners). Long = 2 marks or more (explanations, diagrams, reasoning).
Overall split
- Short (<2 marks)792(91%)
- Long (≥2 marks)77(9%)
Short vs long by chapter
How each chapter's questions divide between short and long.
- Short (<2 marks)
- Long (≥2 marks)
- Organic Chemistry87% short (133) · 13% long (20)
- Electrolysis92% short (98) · 8% long (9)
- Periodic Table, Periodic Properties and Variations of Properties99% short (93) · 1% long (1)
- Mole Concept and Stoichiometry71% short (56) · 29% long (23)
- Metallurgy96% short (71) · 4% long (3)
- Sulphuric Acid94% short (59) · 6% long (4)
- Chemical Bonding89% short (47) · 11% long (6)
- Analytical Chemistry: Uses of Ammonium Hydroxide and Sodium Hydroxide96% short (50) · 4% long (2)
- Acids, Bases and Salts96% short (49) · 4% long (2)
- Study of Compounds – Ammonia91% short (42) · 9% long (4)
- Study of Compounds – Nitric Acid100% short (41) · 0% long (0)
- Practical Work94% short (32) · 6% long (2)
Most short-answer-heavy chapters
Best for quick recall and one-mark practice.
- Study of Compounds – Nitric Acid100%41/4141 of 41 are short (under 2 marks)
- Periodic Table, Periodic Properties and Variations of Properties99%93/9493 of 94 are short (under 2 marks)
- Analytical Chemistry: Uses of Ammonium Hydroxide and Sodium Hydroxide96%50/5250 of 52 are short (under 2 marks)
- Acids, Bases and Salts96%49/5149 of 51 are short (under 2 marks)
- Metallurgy96%71/7471 of 74 are short (under 2 marks)
Most long-answer-heavy chapters
Where higher-mark, explanation-type questions cluster.
How questions are framed
Question types
Share of all questions, by format.
- Short answer61%526
- MCQ16%136
- Fill in the blank5.5%48
- Diagram4.4%38
- Numerical4.3%37
- Reasoning3.1%27
- Difference2.6%23
- Matching2.3%20
- Definition1.4%12
- True/False0.2%2
By marks
Share of all questions, by weight.
- 1 mark91%790
- 1.5 marks0.2%2
- 2 marks5.3%46
- 3 marks2.0%17
- 4 marks0.8%7
- 5 marks0.7%6
- 6 marks0.1%1
By difficulty
Share of all questions, by rating.
- Easy83%724
- Moderate17%145
Diagram load
Chapters where diagram-based questions are most concentrated.
Most diagram-heavy chapters
- Study of Compounds – Ammonia30%14/4614 of 46 carry a diagram
- Periodic Table, Periodic Properties and Variations of Properties20%19/9419 of 94 carry a diagram
- Electrolysis19%20/10720 of 107 carry a diagram
- Acids, Bases and Salts16%8/518 of 51 carry a diagram
- Chemical Bonding15%8/538 of 53 carry a diagram
Share of the chapter's questions that include a diagram.
Year-by-year trends
Shown as a share of each paper, so years stay comparable even though 2021 and 2022 used the reduced semester format with fewer questions.
Short-answer share by year
Percentage of the paper's questions worth less than 2 marks.
Diagram share by year
Percentage of the paper's questions that include a diagram.
Chapter coverage by year
How many questions each chapter contributed to each paper. Darker = more questions.
Chapter × year heatmap
| Chapter | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Acids, Bases and Salts | 5 | 3 | 5 | 4 | 5 | 7 | 1 | 3 | 6 | 10 | 2 |
| Analytical Chemistry: Uses of Ammonium Hydroxide and Sodium Hydroxide | 6 | 7 | 4 | 3 | 5 | 3 | 1 | 11 | 2 | 6 | 4 |
| Chemical Bonding | 5 | 4 | 4 | 5 | 8 | 5 | 5 | 5 | 8 | 4 | |
| Electrolysis | 10 | 9 | 11 | 8 | 13 | 8 | 2 | 14 | 12 | 7 | 13 |
| Metallurgy | 5 | 6 | 7 | 7 | 5 | 10 | 7 | 11 | 4 | 12 | |
| Mole Concept and Stoichiometry | 8 | 10 | 5 | 6 | 10 | 4 | 7 | 8 | 9 | 12 | |
| Organic Chemistry | 12 | 15 | 14 | 19 | 17 | 1 | 13 | 14 | 17 | 17 | 14 |
| Periodic Table, Periodic Properties and Variations of Properties | 12 | 12 | 5 | 10 | 6 | 12 | 10 | 9 | 7 | 11 | |
| Practical Work | 9 | 1 | 3 | 3 | 5 | 4 | 3 | 2 | 4 | ||
| Study of Compounds – Ammonia | 3 | 4 | 3 | 5 | 5 | 7 | 5 | 10 | 4 | ||
| Study of Compounds – Hydrogen Chloride | 2 | 5 | 1 | 6 | 3 | 3 | 2 | ||||
| Study of Compounds – Nitric Acid | 3 | 4 | 5 | 6 | 4 | 6 | 1 | 3 | 6 | 3 | |
| Sulphuric Acid | 4 | 11 | 7 | 8 | 2 | 8 | 8 | 5 | 3 | 7 |
Most frequently tested topics
Recurring topics across chapters.