Question
Question: How does density affect the melting point?...
How does density affect the melting point?
Solution
A high density and high melting point specify a low reactivity; in opposition, low density and low melting point specify high reactivity. The melting point is similar to the heat of sublimation; the density provides a controller to the magnitude of the ionization energy.
Complete step by step answer:
It is not a major factor in defining melting point.
Now is a table of compounds with their densities and melting points.
| Compound | Density/gml−1 | mp/oC |
|---|---|---|
| Hexane | 0.65 | -95 |
| Ethanol | 0.79 | -114 |
| Water | 1.00 | 0 |
| Chloroform | 1.48 | -64 |
| Dimethyl Ether | 1.97 | -141 |
| Sodium chloride | 2.16 | 801 |
| Methyl iodide | 2.28 | -66 |
| Mercury | 13.59 | -39 |
The density increases as we go downcast the list, but the melting opinions vary all over the map.
The intermolecular attractions are considerable more important factors in defining the melting point.
The density and melting point of a metal, engaged together, can give a valuable qualitative controller to the chemical reactivity of the metal. A high density and high melting point require a low reactivity; equally, low density and low melting point require high reactivity. The melting point is similar to the heat of sublimation; the density provides a guide to the magnitude of the ionization energy. These two thermodynamic energy numbers are common to the Born-Haber cycles for the standard electrode potential, enthalpy of creation of the oxide, and reaction with water, which are regularly accepted thermodynamic measures of reactivity. Kinetic effects likewise play a role, not informal to quantify. A strident discontinuity in the overall trend of either melting point or density in the center of a long period points to irregular or infrequent chemical reactivity of the metal.
Note:
Melting point may be well-defined in several ways, each corresponding to a dissimilar residual amount of solid fat.
The term ‘freezing point’ is used on the way to denote the temperature at which a liquid is changed into a solid and can, therefore, be observed as the opposite of the term ‘melting point’.