Difference Between Boiling Point and Melting Point

Main difference

Boiling point and melting point are the terms related to the change of state of matter, as both are the temperatures when intermolecular forces weaken and with increasing kinetic energy molecules change their state of matter. The melting point is the temperature at which the solid begins to turn into a liquid. For example, the melting point of ice is 0°C or 273 K, so at this temperature ice will start to break down as a liquid. The boiling point is the temperature at which the liquid begins to transform into vapors. For example, at room temperature, the boiling point of water is 100 ° C, at this temperature the water molecules begin to evaporate in the form of vapors.

Comparison chart

Boiling point Melting point
Definition The boiling point is the temperature at which the vapor pressure of a liquid is equal to the external pressure surrounding the liquid. The melting point is the temperature at which the solid and liquid phases are in a state of thermal equilibrium.
Physical change The boiling point is the temperature at which the liquid begins to transform into vapors. The melting point is the temperature at which the solid begins to turn into a liquid.
Pressure The boiling point does not stay the same, it changes with the inference of external pressure. The melting point has nothing to do with external pressure.

What is the boiling point?

The boiling point is the temperature at which the vapor pressure of a liquid is equal to the external pressure surrounding the liquid. Typically, this is a high temperature when intermolecular forces weaken and molecules prepare to break bond and evaporate as vapor. External pressure is one of the most notable factors affecting the boiling process, as the higher the external pressure, the higher the boiling point, and the lower the external pressure, the lower the boiling point. The boiling point of water does not stay the same, it changes with the inference of external pressure. For example, at room temperature water has a boiling point of 100°C, although on Mount Everest, where the pressure is about 34kPa, a pint of boiling water is 71°C.

What is the melting point?

The melting point is the temperature at which the solid and liquid phases are in a state of thermal equilibrium. The melting point is generally a property of solids. It is the certain temperature at which solids transform into liquids. As we know, in solids, the molecules hold each other tightly through intermolecular forces, so when it comes to the melting point, the kinetic energy is quite high to release the molecules so they can change the state of matter. Many people who derive from it think that the melting and freezing point of a substance is the same, although it is not mandatory as in the case of agar, which melts at 85C but comes back in solid form at 31C to 40C.

Boiling Point vs. Melting Point

  • The boiling point is the temperature at which the vapor pressure of a liquid is equal to the external pressure surrounding the liquid, while the melting point is the temperature at which the solid and liquid phases are in a state of thermal equilibrium.
  • The melting point is the temperature at which the solid begins to turn into a liquid, while the boiling point is the temperature at which the liquid begins to turn into vapors.
  • The boiling point does not stay the same, it changes with the inference of external pressure, while the melting point has nothing to do with external pressure.
  • The melting and freezing point of a substance is not the same as in the case of agar, which melts at 85C but comes back in solid form at 31C to 40c.
  • The boiling point of water does not stay the same, it changes with the inference of external pressure. For example, at room temperature water has a boiling point of 100°C, although on Mount Everest, where the pressure is about 34kPa, a pint of boiling water is 71°C.

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