Heating Curves

A heating curve is a graphical representation of the temperature change of a substance as it is heated over time, showing phase changes and temperature changes.

A diagonal line indicates that the temperature of the substance is changing.

A flat line indicates that the temperature of the substance remains constant during a phase change.

Melting occurs at the flat line segment where the temperature remains constant while the solid turns into a liquid.

The boiling point is indicated by a flat line segment where the temperature remains constant while the liquid turns into a gas.

The temperature remains constant during a phase change, even though heat is being added.

Point B typically represents the melting point of the substance, where solid and liquid phases coexist.

The melting point is identified at the flat line segment where the temperature does not change as the solid melts into a liquid.

At point A, the substance is in the solid state.

At point C, the substance is in the liquid state.