Liquids

Liquids MDCAT MCQs with answers

48 past paper MCQs from Chemistry unit 4, Liquids, across 4 topics. They are arranged topic by topic; bigger topics show a sample here and link to their full set and to study notes. Tap “Show answer” for the correct option and a short solution.

Practise as a quiz

Properties of Liquids

1.Which type of forces exist between iodine molecules? (MDCAT 2023)

  1. dipole-dipole forces
  2. dipole-induced dipole forces
  3. instantaneous dipole-induced dipole forces
  4. hydrogen bonding
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Correct answer: (c) instantaneous dipole-induced dipole forces

Iodine is non-polar, so only London dispersion forces hold its molecules together.

2.Which of the following is responsible for the low boiling point of diethyl ether as compared to water? (NUMS MDCAT 2025)

  1. Weak intermolecular forces
  2. High surface tension
  3. Low vapour pressure
  4. High vapour pressure
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Correct answer: (a) Weak intermolecular forces

Ether molecules attract each other only by weak dipole forces, while water is held by hydrogen bonds.

3.The weakest intermolecular force present in liquid is? (SZABMU MDCAT 2025)

  1. dipole dipole forces
  2. induce dipole force
  3. Instantaneous dipole induced dipole force
  4. hydrogen bonding
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Correct answer: (c) Instantaneous dipole induced dipole force

London forces between instantaneous dipoles are the weakest of the intermolecular attractions.

All 16 Properties of Liquids MCQs → Properties of Liquids notes →

Evaporation, Vapour Pressure and Boiling Point

4.Vapour pressure is independent of which factor? (MDCAT 2020)

  1. temperature
  2. intermolecular forces
  3. density of the liquid
  4. surface area of the liquid
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Correct answer: (d) surface area of the liquid

A wider surface evaporates more molecules but condenses just as many, so the equilibrium vapour pressure is unchanged.

5.Which of the following factors does not affect the vapour pressure of a liquid? (MDCAT 2022)

  1. amount of liquid
  2. size of molecules
  3. temperature of the liquid
  4. intermolecular forces
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Correct answer: (a) amount of liquid

Vapour pressure is an intensive property; a larger volume of the same liquid at the same temperature has the same vapour pressure.

6.In order to boil water at $110^\circ$C, the external pressure should be: (MDCAT 2024)

  1. 200-760 torr
  2. 760-1200 torr
  3. 665-670 torr
  4. 660-700 torr
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Correct answer: (b) 760-1200 torr

Above $100^\circ$C the vapour pressure of water is above one atmosphere, so the external pressure must be above 760 torr.

All 21 Evaporation, Vapour Pressure and Boiling Point MCQs → Evaporation, Vapour Pressure and Boiling Point notes →

Hydrogen Bonding

7.Which of the following does NOT have a tendency to form hydrogen bonding? (MDCAT 2024)

  1. water
  2. ethyl alcohol
  3. carboxylic acid
  4. hydrocarbon
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Correct answer: (d) hydrocarbon

Hydrogen bonding needs hydrogen bound to a small, strongly electronegative atom, and a hydrocarbon has none.

8.Hydrogen bonding does not exist in: (NUMS MDCAT 2025)

  1. Proteins
  2. Alcohols
  3. Liq HF
  4. SiH4
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Correct answer: (d) SiH4

A hydrogen bond needs hydrogen bound to nitrogen, oxygen or fluorine; silicon is far too weakly electronegative.

9.Which one of the following DO NOT have tendency to form hydrogen bonding? (UHS MDCAT 2024)

  1. Ammonia
  2. Ethyl alcohol
  3. Carboxylic acid
  4. Hydrocarbon
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Correct answer: (d) Hydrocarbon

A hydrocarbon has no hydrogen bound to nitrogen, oxygen or fluorine, so it cannot hydrogen bond.

All 8 Hydrogen Bonding MCQs → Hydrogen Bonding notes →

Anomalous Behaviour of Water

10.Solid water is expanded how many times when compared with the same mass of liquid water? (MDCAT 2020)

  1. 9
  2. 10
  3. 75
  4. 2
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Correct answer: (a) 9

The open hydrogen-bonded cage of ice takes about 9% more room, which is why ice floats and pipes burst.

11.Ice floats on the surface of water due to: (SZABMU MDCAT 2023)

  1. Larger bond length
  2. Cubic structure of ice
  3. Weak intermolecular forces
  4. Empty spaces in the structure of ice
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Correct answer: (d) Empty spaces in the structure of ice

Hydrogen bonds hold the molecules of ice in an open lattice with spaces in it, so ice is less dense than water.

12.What is the reason that ice at 0˚ occupies more volume than water: (UHS MDCAT 2017)

  1. Empty spaces
  2. Ionic bond
  3. Intermolecular
  4. Debye forces
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Correct answer: (a) Empty spaces

Hydrogen bonds hold the molecules of ice in an open lattice with spaces in it.

Anomalous Behaviour of Water notes →

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