MDCAT Chemistry Chapter-wise Weightage: What 16 Years of Past Papers Show
Chemistry is 45 of 180 MCQs in MDCAT. We counted 898 real Chemistry MCQs from 16 past papers to find which chapters carry the marks, and how the recent papers differ from the old ones.
By ParhaiKrlo Team · Published 7 Oct 2026 · 7 min read
Updated: 7 October 2026
Chemistry is the second-biggest subject in MDCAT: 45 of 180 MCQs, or 25% of the paper. Every prep site repeats that figure. What they don't tell you is which chapters those 45 marks actually come from.
We can answer that with real data. ParhaiKrlo's question bank holds every available MDCAT past paper from 2008 to 2025 (there are no papers for 2020 and 2021), and every question is tagged by topic. That gives us 898 Chemistry MCQs to count.
Quick answer
- Chemistry is 45 MCQs (25%) in the current 180-question MDCAT.
- The five most-tested chapters across all 16 papers are s and p Block Elements, Chemistry of Hydrocarbons, Chemical Bonding, Macromolecules and Chemical Equilibrium. Together they make up 376 of 898 questions (41.9%).
- Recent papers have shifted. In 2022 to 2025, Hydrocarbons and Chemical Bonding lead, physical chemistry (equilibrium, atomic structure, gases, thermochemistry) has grown, and Macromolecules and Industrial Chemistry have shrunk sharply.
- A few sub-topics come up again and again: periodic trends, sigma and pi bonds, protein structure, electronic configuration, and Le Chatelier's principle.
- Use the numbers to set priorities, not to skip chapters. Every chapter in PMDC's syllabus can appear.
The official Chemistry weightage
| Subject | MCQs | Weightage |
|---|---|---|
| Biology | 81 | 45% |
| Chemistry | 45 | 25% |
| Physics | 36 | 20% |
| English | 9 | 5% |
| Logical Reasoning | 9 | 5% |
| Total | 180 | 100% |
Chemistry's share has stayed steady over the years. In our data it was 26.7% of the old UHS papers (2008 to 2019), 27.2% of the 200-MCQ PMDC papers (2022 to 2024), and exactly 25% of MDCAT 2025. So past papers are a fair guide to how much Chemistry to expect, which isn't true of Biology. See our MDCAT syllabus guide for the full current pattern.
Chapter-wise weightage from 16 past papers
We counted every active, topic-tagged Chemistry MCQ in the 16 MDCAT papers on ParhaiKrlo. The chapter names are our tags, which follow PMDC's syllabus units.
| Chapter | Past-paper MCQs | % of Chemistry | Priority |
|---|---|---|---|
| s and p Block Elements | 86 | 9.6% | High |
| Chemistry of Hydrocarbons | 86 | 9.6% | High |
| Chemical Bonding | 82 | 9.1% | High |
| Macromolecules | 62 | 6.9% | High |
| Chemical Equilibrium | 60 | 6.7% | High |
| Atomic Structure | 50 | 5.6% | Medium |
| Thermochemistry | 46 | 5.1% | Medium |
| Industrial Chemistry | 44 | 4.9% | Medium |
| Fundamental Concepts of Chemistry | 42 | 4.7% | Medium |
| Electrochemistry | 40 | 4.5% | Medium |
| Gases | 38 | 4.2% | Medium |
| Aldehydes and Ketones | 36 | 4.0% | Medium |
| Reaction Kinetics | 34 | 3.8% | Medium |
| Liquids | 33 | 3.7% | Medium |
| Fundamental Principles of Organic Chemistry | 31 | 3.5% | Medium |
| Alkyl Halides | 28 | 3.1% | Medium |
| Solids | 27 | 3.0% | Medium |
| Alcohols and Phenols | 26 | 2.9% | Low |
| Carboxylic Acids | 26 | 2.9% | Low |
| Transition Elements | 18 | 2.0% | Low |
| Environmental Chemistry | 3 | 0.3% | Low |
Nothing dominates the way Biological Molecules dominates Biology. The marks are spread across many chapters, so broad coverage matters more in Chemistry than in any other subject.
What the recent papers favour
The old UHS papers make up most of the data, so the overall table leans towards what UHS used to ask. Here's what the four PMDC-era papers (2022 to 2025) tested, out of 206 Chemistry MCQs:
| Chapter | MCQs in 2022-2025 | % of recent Chemistry |
|---|---|---|
| Chemistry of Hydrocarbons | 23 | 11.2% |
| Chemical Bonding | 21 | 10.2% |
| s and p Block Elements | 18 | 8.7% |
| Chemical Equilibrium | 15 | 7.3% |
| Atomic Structure | 15 | 7.3% |
| Thermochemistry | 12 | 5.8% |
| Gases | 12 | 5.8% |
| Solids | 11 | 5.3% |
| Reaction Kinetics | 10 | 4.9% |
Two changes stand out:
- Macromolecules fell from 7.9% of Chemistry in the old papers (55 of 692 MCQs) to 3.4% in the recent ones (7 of 206). Most of the old questions were on protein structure.
- Industrial Chemistry fell from 5.9% (41 MCQs) to 1.5% (3 MCQs).
Meanwhile, physical chemistry chapters like Atomic Structure, Gases, Solids, Thermochemistry and Reaction Kinetics take a bigger share than before. Four papers is a small sample, so don't read too much into small differences. But if you're preparing for MDCAT 2027, the recent pattern is the better guide.
The top five chapters in detail
s and p Block Elements: 86 MCQs (9.6%)
Almost half of these questions (40) test periodic trends: atomic radius, ionisation energy, electron affinity and electronegativity. The rest are mostly reactions of Group I, II and IV elements. Learn the trends down a group and across a period until you can answer them instantly. Full topic page.
Chemistry of Hydrocarbons: 86 MCQs (9.6%)
The most-tested chapter in the recent papers. Common questions: the shape of alkenes and their sigma and pi bonds (18), naming alkanes, and the reactivity of benzene. Know the reaction types (substitution, addition, elimination) and the conditions for each. Full topic page.
Chemical Bonding: 82 MCQs (9.1%)
Sigma and pi bonds alone account for 35 questions. Ionic character of covalent bonds, hybridisation, bond energy and VSEPR shapes make up most of the rest. Practise predicting the shape and bond angle of common molecules. Full topic page.
Macromolecules: 62 MCQs (6.9%)
52 of the 62 are on the classification and structure of proteins. This chapter was a favourite in the UHS era but appears much less now, so give it a solid pass without over-investing. Full topic page.
Chemical Equilibrium: 60 MCQs (6.7%)
Evenly spread across Le Chatelier's principle (13), the Haber process (13), buffer solutions (10), solubility products (9) and the common ion effect (7). Expect at least one "what happens if you change the temperature or pressure" question. Full topic page.
High-yield sub-topics to master
These sub-topics appear more often than many whole chapters:
| Sub-topic | Past-paper MCQs |
|---|---|
| Classification and structure of proteins | 52 |
| Periodic trends (radii, ionisation energy, electron affinity, electronegativity) | 40 |
| Sigma and pi bonds | 35 |
| Electronic configuration | 22 |
| Shapes of alkenes (sigma and pi bonds) | 18 |
How to use this data
- Cover every chapter once. Chemistry's marks are spread out, so a skipped chapter costs more here than in other subjects.
- Go deeper on the top five and on recent favourites. Hydrocarbons, Bonding, s and p Block, Equilibrium and Atomic Structure should get your most careful study.
- Learn the textbook line by line. MDCAT Chemistry questions are often direct facts from the FSc textbook: a colour, a condition, a catalyst or an exception.
- Don't neglect numericals. Gases, equilibrium constants, thermochemistry and stoichiometry questions need practice, not just reading.
- Practise by chapter, then by paper. Drill one chapter at a time on the practice page, then sit full MDCAT past papers for timing.
Frequently Asked Questions
What is the weightage of Chemistry in MDCAT?
Chemistry is 45 of 180 MCQs, or 25% of the current MDCAT paper. Its share has stayed steady: 26.7% of the old UHS papers (2008 to 2019), 27.2% of the 200-MCQ PMDC papers (2022 to 2024), and exactly 25% of MDCAT 2025.
Which Chemistry chapters are most important for MDCAT?
Across 898 past-paper MCQs from 2008 to 2025, the five most-tested chapters are s and p Block Elements (86), Chemistry of Hydrocarbons (86), Chemical Bonding (82), Macromolecules (62) and Chemical Equilibrium (60). Together they make up 376 questions, or 41.9% of all Chemistry MCQs.
Have recent MDCAT papers changed which Chemistry chapters are tested?
Yes. In the 2022 to 2025 papers, Chemistry of Hydrocarbons and Chemical Bonding lead, and physical chemistry chapters like Atomic Structure, Gases, Solids, Thermochemistry and Reaction Kinetics take a bigger share. Macromolecules fell from 7.9% of Chemistry in the old papers to 3.4%, and Industrial Chemistry fell from 5.9% to 1.5%.
Which Chemistry sub-topics come up most in MDCAT?
Classification and structure of proteins (52 MCQs), periodic trends such as radii, ionisation energy, electron affinity and electronegativity (40), sigma and pi bonds (35), electronic configuration (22), and the shapes of alkenes (18). These appear more often than many whole chapters.
Can I skip low-weightage Chemistry chapters?
No. Chemistry's marks are spread across many chapters, so a skipped chapter costs more here than in other subjects. Cover every chapter once, then go deeper on the top five and on the chapters recent papers favour.
Next steps
- MDCAT Physics chapter-wise weightage: the same analysis for Physics.
- MDCAT Biology chapter-wise weightage: Biology, the biggest subject.
- Chemistry syllabus: every topic and sub-topic.
- Full-length MDCAT mocks: test yourself under exam conditions.
All counts are from ParhaiKrlo's own verified bank of MDCAT past papers (2008 to 2019 and 2022 to 2025), counted on 7 October 2026. Chapter names are our topic tags. Counts can shift slightly if questions are re-verified. The 45-MCQ weightage is PMDC's current MDCAT pattern.