The melting point of a substance is equivalent to its

Analyze the question The question asks which property is equivalent to the melting point. Melting point is the temperature at which a solid changes to a liquid.

Explain the concept Melting and freezing (solidification) are reverse processes that happen at the same temperature for a pure substance at a given pressure.

• Melting: solid → liquid (absorbs latent heat of fusion)
• Freezing/solidification: liquid → solid (releases latent heat of fusion)

For example, ice melts at 0 °C, and water freezes at 0 °C. At this temperature, solid and liquid coexist in equilibrium.

Check each option

• A. Vapour pressure: This is a pressure, not a temperature. It relates to evaporation or boiling, not melting. Wrong.
• B. Solidification temperature: This is the temperature at which the liquid turns to solid. It is the same as the melting point. Correct.
• C. Liquidification temperature: This is a loosely worded term. If it means the temperature at which a solid becomes liquid, that is just the melting point restated, and it could also be confused with condensation (gas to liquid). It is not the standard term, so it is not the best answer.
• D. Solidification pressures: Melting point is a temperature, not a pressure. Wrong.

Answer The melting point equals the solidification (freezing) temperature, which is option B.

Exam tip Remember: melting point = freezing point. They are the same temperature, approached from opposite directions. When a question asks for an "equivalent" of melting point, look for freezing or solidification temperature. Also watch the units: if an option is a pressure, it cannot be equal to a temperature.