Which statement about determining the melting point in a classroom is incorrect?

Which statement about determining the melting point in a classroom is incorrect?

• A. Gradually heat a sample and record the temperature at which it changes from solid to liquid.
• B. Rapidly heat a sample to observe melting point.
• C. Record the temperature at which the liquid boils.
• D. Observe a color change as the sample heats.

Answer: (B)

Melting point is the temperature at which a solid begins to turn into a liquid, and in a classroom you determine it by heating slowly and watching for the solid to melt. Heating gradually lets you observe the exact temperature where melting starts (and, if needed, where it finishes), which is essential for a precise measurement. If you heat rapidly, you’re likely to overshoot the melting point or miss the onset of melting entirely, giving an inaccurate reading. A gradual approach gives a reliable, observable transition. The other prompts fit better with this goal: gradually heating and recording the melting transition matches the method, boiling point is a different property, and a color change isn’t a dependable indicator of melting.

Melting point is the temperature at which a solid begins to turn into a liquid, and in a classroom you determine it by heating slowly and watching for the solid to melt. Heating gradually lets you observe the exact temperature where melting starts (and, if needed, where it finishes), which is essential for a precise measurement. If you heat rapidly, you’re likely to overshoot the melting point or miss the onset of melting entirely, giving an inaccurate reading. A gradual approach gives a reliable, observable transition.

The other prompts fit better with this goal: gradually heating and recording the melting transition matches the method, boiling point is a different property, and a color change isn’t a dependable indicator of melting.