Question

complete the statements by writing the number from the graph. the substance is in the gas phase only in region . the substance is in both the liquid and the solid phase in region . the substance is in only the liquid phase in region . the melting point is the temperature at region . the boiling point is the temperature at region . done

Explanation:

Step1: Understand phase - change concepts

In a temperature - time graph for a substance, the flat regions represent phase - changes. The substance is in the gas phase when the temperature is above the boiling point and rising. The flat region at the higher temperature is the boiling point (region 4), and after that, in region 5, the substance is only in the gas phase.

Step2: Identify solid - liquid phase region

The flat region at the lower temperature is the melting point. During melting, the substance is in both the solid and liquid phases. This is region 2.

Step3: Determine liquid - only phase region

Between the melting and boiling points, when the temperature is rising and there is no phase - change (no flat region), the substance is in the liquid phase only. This is region 3.

Step4: Locate melting point

The melting point is the temperature at which the substance changes from solid to liquid. It is represented by the flat region at the lower temperature, which is region 2.

Step5: Locate boiling point

The boiling point is the temperature at which the substance changes from liquid to gas. It is represented by the flat region at the higher temperature, which is region 4.

Answer:

The substance is in the gas phase only in region 5.
The substance is in both the liquid and the solid phase in region 2.
The substance is in only the liquid phase in region 3.
The melting point is the temperature at region 2.
The boiling point is the temperature at region 4.