Question

a substance is placed in a closed vessel. the substance is continuously heated and its temperature is monitored, leading to the heating curve below. five regions of the heating curve are labeled with a number. during which numbered region(s) of the graph does the addition of heat lead to a temperature change? select all that apply. tap to select or deselect an answer select all that apply 1 2 3 4 5

Explanation:

• In a heating curve, when heat is added and temperature changes, it means the substance is in a single - phase (solid, liquid, or gas) and not undergoing a phase change.
• Region 1: The substance is in the solid phase and temperature is increasing as heat is added.
• Region 3: The substance is in the liquid phase and temperature is increasing as heat is added.
• Region 5: The substance is in the gas phase and temperature is increasing as heat is added.
• Region 2: The substance is undergoing a phase change (solid - to - liquid, melting) and temperature remains constant.
• Region 4: The substance is undergoing a phase change (liquid - to - gas, boiling) and temperature remains constant.

Answer:

1, 3, 5