Compounds molecular/covalent

In molecular covalent compounds, intermolecular forces are very weak in comparison with intramolecular forces. For this reason, most covalent substances with a low molecular mass are gaseous at room temperature. Others, with higher molecular masses may be liquids or solids, though with relatively low melting and boiling points. 

Every syllable in the name of a chemical compound conveys something about that compound. From ionic and molecular (covalent) compounds to organic hydrocarbons and acids, the names matter, and you find out why in this part. 

Naming Molecular (CoValent) Compounds and Writing Their Formulas... 

Does the formula contain a metal (not hydrogen) If there s no metal, you re naming a molecular (covalent) compound, so you need to use the prefixes in Table 6-2. Be sure to change the ending of the second element to -ide. If there is a metal, then you re dealing with an ionic compound, so proceed to Question 3. 

Molecule Basic unit for molecular (covalent) compounds. 

The name of a molecular compound reveals its composition and is important in communicating the nature of the compound. Figure 9-9 can help you determine the name of a molecular covalent compound. 

Form ionic compounds with metals and molecular (covalent) compounds with other nonmetals... 

Knowledge of the relative values of ionization energies assists us in predicting whether an element is likely to form ionic or molecular (covalent) compounds. Elements with low ionization energies form ionic compounds by losing electrons to form cations (positively... 

Can you explain why network covalent compounds have much higher melting points than molecular covalent compounds ... 

In most covalent compounds, the strong covalent bonds link the atoms together into molecules, but the molecules themselves are held together by much weaker forces, hence the low melting points of molecular crystals and their inability to conduct electricity. These weak intermolecular forces are called van der WaaFs forces in general, they increase with increase in size of the molecule. Only... 

A normal oxide is a binary (two element) compound containing oxygen in the -2 oxidation state. BaO is an example of an ionic oxide and S02 is an example of a molecular (covalent) oxide. 

The initial product of the inhibition step is not known in this case and may be a molecular complex.8 The direct reaction of the ethane with the peroxy radical is an example of a covalent compound giving a reaction resembling that of a related free radical. The molecular weight determination by Gomberg was therefore a necessary part of the proof that he was dealing with radicals and not merely an unusually reactive hydrocarbon. The presence of free radicals has since been confirmed by measurements of the paramagnetic susceptibility and the paramagnetic resonance absorption.9-10 The latter evidence also rules out an alter-... 

If a nonmetal reacts with another nonmetal no electrons are lost or gained, but are shared. We call such compounds covalent (molecular) compounds. These compounds contain small units we call molecules. Ammonia, NH3, water, H20, and methane, CH4, are examples of covalent compounds. 

Still another model to represent the bonding that takes place in covalent compounds is the molecular orbital theory. In the molecular orbital (MO) theory of covalent bonding, atomic orbitals (AOs) on the individual atoms combine to form orbitals that encompass the... 

M. M. Siegel, K. Tabei, G. A. Bebernitz, E. Z. Baum Rapid methods for screening low molecular mass compounds non-covalently bormd to proteins using size exclusion and mass spectrometry applied to inhibitors of human... 

Although the MEG model is essentially ionic in nature, it may also be used to evaluate interactions in partially covalent compounds by appropriate choices of the wave functions representing interacting species. This has been exemplified by Tossell (1985) in a comparative study in which MEG treatment was coupled with an ab initio Self Consistent Field-Molecular Orbital procedure. In this way, Tossell (1985) evaluated the interaction of C03 with Mg in magnesite (MgC03). Representing the ion by a 4-31G wave function, holding its... 

To sum up all the experimental evidence whereas AU11L7X3 and smaller molecular cluster compounds are covalently bonded and show no tendency toward metallic binding, the bonding in Au55(PPh3),2Cl6 is delocalized, non-directional, and substantially metallic in character. 

Nonmetals tend to form covalent bonds with one another (see Chapter 5 for details). Compounds made up of nonmetals held together by one or more covalent bonds are called molecular (or covalent) compounds. 

---