Boiling points of covalent hydrides

Boiling points of covalent hydrides are discussed in Section 16.1. 

Boiling Points of the Covalent Binary Hydrides of Groups 4A, 5A, 6A, and 7A... 

Because most of the covalent hydrides consist of molecular units with only weak intermolecular forces between them, they are volatile compounds. Accordingly, the covalent hydrides are sometimes referred to as the volatile hydrides. The nomenclature, melting points, and boiling points of several covalent hydrides are shown in Table 6.6. 

The boiling points of the covalent hydrides of elements in Croup 6... 

The boiling points of the covalent hydrides of the elements in Groups 4A, 5A, 6A, and 7A. The dashed line shows the expected boiling point of water if it had no hydrogen bonding. 

Boron and hydrogen form many compounds and they exhibit unusual structural forms. Several of the boranes are listed in Table 13.2. Covalent hydrides are generally compounds that have low boiling points. Consequently, they are often referred to as volatile hydrides. 

We see then a gradation from purely ionic to purely covalent bonding in different molecules, and this is manifest in their chemical and physical properties. Consider, for instance, the hydrides of the elements in the second horizontal row of the periodic table. Their melting and boiling points,7 where known, are given below. 

Covalent metal hydrides are compounds ofhydrogen and non-metals. Here, atoms of similar electronegativities share electron pairs. In general, covalent hydrides have low melting and boiling points. Because of the weak van der Waals forces between... 

Table 14 Covalent hydrides of the elements of the groups 14, 15, and 16 of the periodic table, and their boiling points (K)...

Covalent hydrides are formed when hydrogen combines with other nonmetals. We have encountered many of these compounds already HCl, CH4, NH3, H2O, and so on. The most important covalent hydride is water. The polarity of the H2O molecule leads to many of water s unusual properties. Water has a much higher boiling point than is expected from its molar mass. It has a large heat of vaporization and a large heat capacity, both of which make it a very useful coolant. Water has a higher density as a hquid than as a sohd because of the open structure of ice, which results from maximizing the... 

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