What is misleading with the term melting point?

Answer 1

The term "melting point" is misleading because the melting point is dependent on both the amount pressure and heat applied. At 1 atm (atmosphere), the melting point is called the "normal melting point." The amount of heat necessary to melt a substance at it's normal melting point is consistent with the substance's generally accepted melting point; like 0ºC for H2O. When the amount of pressure is changed, the amount of heat necessary to melt the substance also changes, therefore completely altering the melting point of said substance. For example, 1 atm is usually found at sea level, so the amount of heat having to be added to a substance to melt it at that altitude is equal to it's normal melting point. When attempting to melt the same substance at higher altitudes, (higher altitudes will contain more than 1 atm of pressure) the substance will not require as much heat as it did while melting at sea level. As previously mentioned, H2O converts from ice into water at 0ºC while under 1 atm of pressure (normal melting point). However, in an altitude of 10,000ft the melting point of H2O may change to something like -6ºC opposed to the generally accepted 0ºc.

Tl;dr- The term "melting point" is misleading, because it leads us to believe that the melting point will always be consistent in a substance. However, in reality the "melting point" is only consistent to a given amount of pressure the substance is undergoing.

*atm (atmosphere) is a unit of measurement to convey a given amount of pressure. It's usually is used to convey the amount of pressure in altitudes.

Answer 2

Melting point of a crystalline organic compound is defined as a definite and sharp temperature at which a solid starts melting .Actually in practice, we can only observe the melting range i.e. the difference between the temperature at which the collapse of the crystals is observed and the temperature at which the sample becomes completely liquid. In pure crystalline organic substances the range is nearly 0.5 deg C.
Hence actually speaking the melting point is a range over which the melting process is taking place and is not a fixed temperature .As the amount of impurities in the substance increases ,it also increases the range of melting point.

Answer 3

The term "melting point" can be misleading because it implies a single temperature at which a substance changes from solid to liquid. In reality, substances can have a range of temperatures over which they transition from solid to liquid, depending on factors like pressure and impurities.