Polar covalent bonding prediction

Comparing polarity between components is often a good way to predict solubility, regardless of whether those components are liquid, solid, or gas. Why is polarity such a good predictor Because polarity is central to the tournament of forces that underlies solubility. So solids held together by ionic bonds (the most polar type of bond) or polar covalent bonds tend to dissolve well in polar solvents, like water. 

Electronegativities also give us a simple way of predicting which atom in a polar covalent bond has the partial negative charge and which has the partial positive charge. 

The VSEPR model correctly predicts that Bep2 is linear with two identical Be—F bonds. How can we use valence-bond theory to describe the bonding The electron configuration of F (ls 2s 2p ) indicates an unpaired electron in a 2p orbital. This electron can be paired with an unpaired Be electron to form a polar covalent bond. Which orbitals on the Be atom, however, overlap with those on the F atoms to form the Be — F bonds ... 

In these complexes of A1(CH3)3 the dative D Al bond distances are 20-30 pm longer than the single, polar covalent bond distances between the same atom pair predicted by the MSS rule. 

The covalent bond formed from two sp hybridized carbon atoms is predicted to be relatively strong when compared to a polarized covalent bond (it is much... 

Because F is more electronegative than B, one predicts that C-F is the more polarized covalent bond. 

Predict whether the carbon-metal bond in these organometallic compounds is nonpolar covalent, polar covalent, or ionic. For each polar covalent bond, show the direction of its polarity using the symbols 5-1- and 5-. 

Electronegativity is a scale used to determine an atom s attraction for an electron in the bonding process. Differences in electronegativities are used to predict whether the bond is pure covalent, polar covalent, or ionic. Molecules in which the electronegativity difference is zero are considered to be pure covalent. Those molecules that exhibit an electronegativity difference of more than zero but less than 1.7 are classified as polar covalent. Ionic crystals exist in those systems that have an electronegativity difference of more than 1.7. 

Describe how electronegativity differences are used to predict whether a bond is pure covalent, polar covalent, or ionic. 

For example, atoms of both the alkaline-earth family (ZAval = 2) and the chalcogen family (ZAval = 6) correspond to FAemp = 2, and their stoichiometric proportionality (or coordination number) to monovalent atoms is therefore commonly two (AH2, ALi2, AF2, etc.). It is a remarkable and characteristic feature of chemical periodicity that the empirical valency FAemp applies both to covalent and to ionic limits of bonding, so that, e.g., the monovalency of lithium (Vuemp = 1) correctly predicts the stoichiometry and coordination number of covalent (e.g., Li2), polar covalent (e.g., LiH), and extreme ionic (e.g., LiF) molecules. Following Musher,132 we can therefore describe hypervalency as referring to cases in which the apparent valency FA exceeds the normal empirical valency (3.184),... 

An obvious use of an electronegativity scale is to predict the direction of electrical polarity of a covalent bond with ionic character. Table 2.2 tells us that the C—H bond in alkanes (CnH2n+2) is polar in the same sense as the 0—H bonds in water, although to a much lesser degree ... 

PROBLEM 7.1 Use the electronegativity values in Figure 7.4 to predict whether the bonds in the following compounds are polar covalent or ionic ... 

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