Free IB DP Practice Questions | RevisionPrep

1FoundationMCQProperties of matter1 markPaper 1~2 min

A student tests three unlabelled solids: iodine (

\text{I}_2

), sodium chloride (NaCl), and copper (Cu). A small sample of each is added to water; the electrical conductivity of each mixture is then measured. Iodine is insoluble and its mixture does not conduct; sodium chloride dissolves and its solution conducts; copper is insoluble and its mixture does not conduct. Which explanation accounts for all three observations?

Solutions

2FoundationMCQProperties of matter1 markPaper 1~2 min

A pure substance is heated at constant pressure from

-50\ ^\circ\text{C}

to

150\ ^\circ\text{C}

. A temperature–time graph shows two horizontal plateaus: one at

0\ ^\circ\text{C}

, where solid and liquid coexist, and one at

100\ ^\circ\text{C}

, where liquid and gas coexist. Which row correctly identifies the phase change occurring at each plateau and the substance?

Solutions

3FoundationMCQProperties of matter1 markPaper 1~2 min

A student measures the mass of a 25.0 cm³ sample of an unknown liquid at 20 °C and finds it to be 19.75 g. She transfers the liquid into a 50.0 cm³ volumetric flask and adds distilled water to the graduation mark. The resulting solution has a density of 1.02 g cm⁻³. What is the density of the original liquid?

Solutions

4FoundationMCQMolecular theory and the nature of matter1 markPaper 1~2 min

Dalton's atomic theory included the postulate that all atoms of a given element are identical in mass. Which 20th-century discovery directly contradicts this postulate?

Solutions

5FoundationMCQProperties of matter1 markPaper 1~2 min

A non-polar molecular compound has low electrical conductivity, takes the shape of its container, has a fixed volume at constant temperature and pressure, and shows negligible change in volume when the applied pressure is increased from

100\ \text{kPa}

to

500\ \text{kPa}

. Which combination of properties is consistent with this description?

Solutions

6FoundationMCQProperties of matter1 markPaper 1~2 min

A few drops of ethanol (

\text{C}_2\text{H}_5\text{OH}

, boiling point

78\ ^\circ\text{C}

) placed on the back of a hand produce a noticeable cooling sensation. Which property of ethanol is the primary reason for this observation?

Solutions

7FoundationMCQProperties of matter1 markPaper 1~2 min

An iron nail is left outside and gradually forms rust (hydrated iron(III) oxide). The mass of the rusted nail is greater than the mass of the original nail. Which statement best explains this observation in terms of the particulate nature of matter?

Solutions

8FoundationMCQSolid, liquid, gas phases and changes of state1 markPaper 1~2 min

At 25 °C, three pure substances W, X, and Y are observed. W has a fixed volume, takes the shape of its container, and its particles are close together but able to flow past one another. X has a fixed shape and fixed volume, with particles arranged in a regular lattice and undergoing only vibrational motion. Y has no fixed shape or volume, its particles move rapidly and independently, and it expands to fill any container. Which row correctly identifies the states of matter of W, X, and Y?

Solutions

9FoundationMCQMolecular theory and the nature of matter1 markPaper 1~2 min

Dalton's atomic theory proposed that all atoms of a given element are identical and have the same mass. Which experimental observation most directly contradicts this postulate?

Solutions

10FoundationMCQMolecular theory and the nature of matter1 markPaper 1~2 min

A student burns

12\ \text{g}

of carbon in excess oxygen, producing

44\ \text{g}

of carbon dioxide. Dalton's atomic theory states that atoms are neither created nor destroyed in a chemical reaction, and that chemical reactions involve the rearrangement of atoms. Which conclusion is best supported by this experiment within the context of Dalton's theory?

Solutions

11FoundationMCQProperties of matter1 markPaper 1~2 min

A white crystalline solid has a melting point of 801 °C. It does not conduct electricity in the solid state, but conducts well when molten. Which type of bonding is present in this solid?

Solutions

12FoundationMCQMolecular theory and the nature of matter1 markPaper 1~2 min

A sealed rigid container holds an ideal gas. When the container is heated, the pressure of the gas increases. Which statement from kinetic molecular theory best explains this observation?

Solutions

13FoundationMCQMolecular theory and the nature of matter1 markPaper 1~2 min

A drop of food colouring is added to a beaker of hot water and an identical drop is added to a beaker of cold water. The colouring disperses significantly faster in the hot water. Which statement provides the most direct molecular explanation for this observation?

Solutions

14FoundationMCQSolid, liquid, gas phases and changes of state1 markPaper 1~2 min

The phase of carbon dioxide shows a triple point at

5.11 \text{ atm}

and

-56.6°\text{C}

, and a critical point at

73.0 \text{ atm}

and

31.1°\text{C}

. A sample of solid carbon dioxide is placed in a sealed, rigid container at

1.00 \text{ atm}

and

-80°\text{C}

. The container is warmed to

-50°\text{C}

while maintaining a constant pressure of

1.00 \text{ atm}

. Which statement correctly describes the physical change that occurs?

Solutions

15FoundationMCQMolecular theory and the nature of matter1 markPaper 1~2 min

A student places a few crystals of potassium manganate(VII) at the bottom of a beaker of water at room temperature. Over several hours, the purple colour spreads throughout the water without stirring. Which statement best explains this observation in terms of the kinetic molecular theory?

Solutions

16FoundationMCQSolid, liquid, gas phases and changes of state1 markPaper 1~2 min

The triple point of iodine occurs at approximately

113\ ^\circ\text{C}

and

0.12\ \text{atm}

. A student heats a sample of pure solid iodine at standard atmospheric pressure (

1\ \text{atm}

) and observes that it converts directly to a purple vapour without forming a liquid. Which statement best explains this observation?

Solutions

17FoundationMCQSolid, liquid, gas phases and changes of state1 markPaper 1~2 min

A sealed syringe contains

20.0 \ \text{cm}^3

of nitrogen gas at

1.00 \ \text{atm}

and

25 \ ^\circ\text{C}

. The plunger is pushed in rapidly until the volume is

10.0 \ \text{cm}^3

, while the temperature remains constant at

25 \ ^\circ\text{C}

. Which of the following correctly describes the nitrogen molecules after compression compared to before?

Solutions

18FoundationMCQProperties of matter1 markPaper 1~2 min

A sealed syringe contains

20 \ \text{cm}^3

of air at room temperature. The plunger is pushed in, reducing the volume to

10 \ \text{cm}^3

at constant temperature. Which statement correctly describes the change in the particulate behaviour of the air?

Solutions

19FoundationMCQProperties of matter1 markPaper 1~2 min

The boiling point of an unknown colourless liquid is measured as

100\ ^\circ\text{C}

at standard pressure. The three candidate substances are water (

\text{H}_2\text{O}

, bp

= 100\ ^\circ\text{C}

), ethanol (

\text{C}_2\text{H}_5\text{OH}

, bp

= 78\ ^\circ\text{C}

), and hexane (

\text{C}_6\text{H}_{14}

, bp

= 69\ ^\circ\text{C}

). Which identity is correct, and what is the best explanation for why this substance has the highest boiling point of the three?

Solutions

20FoundationMCQSolid, liquid, gas phases and changes of state1 markPaper 1~2 min

Liquid mercury is poured into a glass graduated cylinder at room temperature and forms a convex meniscus. Which statement best explains why mercury forms a convex rather than a concave meniscus in glass?

Solutions

Introduction to the Particulate Nature of Matter · Paper 1 — Free Chemistry HL Practice Questions