MDCAT Chemistry — Fundamental Concepts of Chemistry
Fundamental Concepts of Chemistry is a core Chemistry topic in the PMDC MDCAT syllabus, covering 7 subtopics. Below are the subtopics to revise, how often the topic appears in past papers, and real past-paper MCQs to try.
Subtopics (7)
- Chromatography Techniques
- Concentration Units (ppm, Molarity)
- Limiting and Excess Reactants
- Moles and Avogadro's Number
- Purification Techniques (Sublimation, Crystallization)
- Stoichiometry
- Yield (Theoretical, Actual, Percentage)
How Fundamental Concepts of Chemistry is tested
Across the 16 MDCAT past papers on ParhaiKrlo, Fundamental Concepts of Chemistry accounts for 42 questions. It appears in 15 of them, about 2.8 questions a paper. The heaviest was MDCAT 2009, with 5 questions, and the most recent is MDCAT 2025, with 3.
| Paper | Questions |
|---|---|
| MDCAT 2025 | 3 |
| MDCAT 2024 | 2 |
| MDCAT 2022 | 1 |
| MDCAT 2019 | 3 |
| MDCAT 2018 | 3 |
| MDCAT 2017 | 3 |
| MDCAT 2016 | 1 |
| MDCAT 2015 | 3 |
| MDCAT 2014 | 1 |
| MDCAT 2013 | 2 |
| MDCAT 2012 | 3 |
| MDCAT 2011 | 3 |
| MDCAT 2010 | 4 |
| MDCAT 2009 | 5 |
| MDCAT 2008 | 5 |
Fundamental Concepts of Chemistry MCQs from the MDCAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · MDCAT 2025 · Fundamental Concepts of Chemistry
Given: 2H₂ + O₂ → 2H₂O. If 4 g of H₂ reacts with 32 g of O₂ to produce 28 g of H₂O, what is the percentage yield? (Molar mass: H₂ = 2 g/mol, O₂ = 32 g/mol, H₂O = 18 g/mol)
- A.63.6%
- B.77.8%
- C.87.5%
- D.92.5%
Show answer
Answer: B. 77.8% — With 4 g H2 and 32 g O2 reacting completely to give 28 g H2O, the percentage yield is 77.8%.
- Q2 · MDCAT 2024 · Fundamental Concepts of Chemistry
Number of moles in an element is directly proportional to:
- A.Mass of an element
- B.Empirical formula mass
- C.Molar mass of an element
- D.Formula mass
Show answer
Answer: A. Mass of an element — Moles = mass ÷ molar mass, so at a fixed molar mass, moles are directly proportional to mass.
- Q3 · MDCAT 2022 · Fundamental Concepts of Chemistry
One a. m .u stands for
- A.An atom of C - 12
- B.1/12th of a carbon
- C.1/12th of H
- D.1 atom of all the elements
Show answer
Answer: B. 1/12th of a carbon — 1 a.m.u (atomic mass unit) is defined as exactly 1/12th of the mass of a Carbon-12 atom.