MDCAT Chemistry — Liquids
Liquids is a core Chemistry topic in the PMDC MDCAT syllabus, covering 6 subtopics. Below are the subtopics to revise, how often the topic appears in past papers, and real past-paper MCQs to try.
Subtopics (6)
- Colligative Properties of Solutions
- Evaporation, Boiling Point, Vapor Pressure
- Hydrogen Bonding
- Intermolecular Forces (Van der Waals)
- Properties of Liquids (Kinetic Theory)
- Solubility and Solubility Curves
How Liquids is tested
Across the 16 MDCAT past papers on ParhaiKrlo, Liquids accounts for 33 questions. It appears in 15 of them, about 2.2 questions a paper. The heaviest was MDCAT 2008, with 6 questions, and the most recent is MDCAT 2025, with 1.
| Paper | Questions |
|---|---|
| MDCAT 2025 | 1 |
| MDCAT 2024 | 3 |
| MDCAT 2023 | 2 |
| MDCAT 2022 | 1 |
| MDCAT 2019 | 2 |
| MDCAT 2018 | 1 |
| MDCAT 2017 | 1 |
| MDCAT 2016 | 3 |
| MDCAT 2015 | 1 |
| MDCAT 2014 | 3 |
| MDCAT 2013 | 3 |
| MDCAT 2012 | 3 |
| MDCAT 2011 | 2 |
| MDCAT 2010 | 1 |
| MDCAT 2008 | 6 |
Liquids MCQs from the MDCAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · MDCAT 2025 · Liquids
Which one of the following has a higher vapour pressure?
- A.Acetone
- B.Acetaldehyde
- C.Isopentane
- D.Benzene
Show answer
Answer: C. Isopentane — The official key marks C (isopentane). On the physical data acetaldehyde is higher: it boils at 20.2°C against isopentane's 27.8°C, and a lower boiling point means a higher vapour pressure.
- Q2 · MDCAT 2024 · Liquids
In order to boil water at 110°C, external pressure should be
- A.200-760 torr
- B.760-1200 torr
- C.665-670 torr
- D.660-700 torr
Show answer
Answer: B. 760-1200 torr — Boiling above the normal 100°C boiling point (like 110°C) requires external pressure above 1 atm (760 torr).
- Q3 · MDCAT 2023 · Liquids
Which is not a property of liquid?
- A.Osmotic pressure
- B.Freezing point
- C.Diffusion
- D.Melting
Show answer
Answer: D. Melting — Melting is not a property of liquids — it describes a solid's transition into a liquid, not a property a liquid itself has.