The main difference between boiling point and melting point is that boiling point is the temperature at which a liquid state changes to its gaseous state whereas melting point is the temperature at which a solid state changes to a liquid state .
There are three states of matter: solid state, liquid state and gaseous state. If we change the temperature of that substance then matter can change from one particular state to another. When heated, a solid usually changes to its liquid state; And on further heating, it changes to its gaseous state. Conversely, if we cool a gaseous compound, it changes to a liquid state, followed by a solid state on further cooling. However, there are some solids that can go directly to the gaseous state without going through the liquid state (we call this sublimation), and vice versa.
1. Overview and Key Difference
2. What is Boiling Point
3. What is Melting Point
4. Side by Side Comparison – Boiling Point vs Melting Point in Tabular Form
6. Summary
What is boiling point?
Boiling point is the property of a liquid. Boiling point is the temperature at which the vapor pressure of a liquid is equal to the external pressure on the liquid. Pressure is a major factor that affects the boiling point; The greater the external pressure on a substance, the higher the boiling point. Thus, this is the simple principle behind the pressure cooker. A pressure cooker is a cooker that traps steam with hot water inside it. The high amount of vapor inside the container creates external pressure on the liquid. Consequently, this higher pressure results in a higher boiling point. Also, this principle is very useful, especially at high altitudes. Typically, water boils at 100 0 C. Since atmospheric pressure is lower at higher altitudes, water will boil between 80 0 C – 90 0 C. And, it will lead to undercooked food.
A liquid boils when it exceeds its saturation temperature at the corresponding saturation pressure. The saturation temperature is the temperature corresponding to the highest thermal energy that the liquid can hold at a given pressure without changing the state of the vapor. The saturation temperature is also equal to the boiling point of the liquid. The boiling point occurs when the thermal energy of the liquid is sufficient to break the intermolecular bonds. Normal boiling point is the saturation temperature at atmospheric pressure. Furthermore, the boiling point differs only between the triple point and critical point of the liquid.
What is melting point?
Melting point is a property of a solid. The melting point is the temperature at which a solid turns into a liquid. More precisely, the melting point is the temperature when the liquid state and the solid state are in thermal equilibrium with each other.
The melting point and freezing point of a substance cannot be the same. For example, agar melts at 85 0 C, but it solidifies back at 31 0 C to 40 0 C. Intermolecular bonds and molecular weight mostly define the melting point. Some solids, such as glass, do not have a specific melting point. They simply go through a smooth transition from solid to liquid.
What is the difference between boiling point and melting point?
Boiling point and melting point are properties of matter. The main difference between boiling points and melting points is that boiling point is the temperature at which a liquid state changes to its gaseous state whereas melting points is the temperature at which a solid state changes to a liquid state. Therefore, the boiling points is defined for a liquid state while the melting points is defined for the solid state.
The below info-graphic presents more details on the difference between boiling point and melting point.
Summary
Both boiling point and melting point are properties of matter. They play a very important role when describing a material. The main difference between boiling point and melting point is that boiling point is the temperature at which a liquid state changes to its gaseous state whereas melting point is the temperature at which a solid state changes to a liquid state.
