BPSC CCE Prelims
States of Matter Previous Year Questions (PYQs)

Detailed Explanation:

Matter with no fixed shape but fixed volume is a liquid.

✅ Kerosene is a liquid – has fixed volume but takes the shape of its container.

❌ Carbon steel is a solid – has both fixed shape and fixed volume.

❌ Krypton is a noble gas – has neither fixed shape nor fixed volume.

Detailed Explanation:

✅ Option 1 – Ripening of fruit: This is an irreversible change (fruit cannot be un-ripened).
✅ Option 2 – Setting of cement: This is an irreversible change (cement cannot return to powder form once set).
✅ Option 3 – Burning of coal: This is an irreversible change (coal once burned cannot be recovered).

All three options represent irreversible changes, so none of them is the odd one out. Hence, Option 5 (None of the above) is correct.

Detailed Explanation:

Avogadro's law states that under the same temperature and pressure, equal volumes of all gases contain equal number of molecules.

• Core Principle: Discovered by Amedeo Avogadro (1812), this fundamental gas law directly matches the question's description.
• Therefore, Avogadro's law is the correct answer, making Option 3 correct.

Detailed Explanation:

The triple point is a unique thermodynamic condition where all three phases of a substance—solid, liquid, and gas—coexist in equilibrium at a specific temperature and pressure.

Boiling point (liquid to gas), melting point (solid to liquid), and freezing point (liquid to solid) each involve transitions between only two phases, not all three simultaneously.

Therefore, the triple point is where all three states coexist, making Option 4 the correct answer.