Methane, bond angles molecular model

The concept of hybridization of atomic orbitals was subsequently introduced, in an attempt to interpret the difference between the actual bond angle for the water molecule and the value of 90° considered in the previous model. This concept had already been introduced to interpret, for example, the tetrahedral geometry of the methane molecule. We shall come back to this subject later in the chapter, to conclude that, although it is possible to establish a correlation between molecular geometry and hybrid orbitals, it is not correct to take the latter as the basis of an explanation of the former. This distinction is very important in teaching. 

Since compounds of carbon are held together chiefly by covalent bonds, organic chemistry, too, is much concerned with molecular size and shape. To help us in our study, we should make frequent use of molecular models. Figure 1.11 shows methane as represented by three different kinds of models stick-and-ball, framework, and space-filling. These last are made to scale, and reflect accurately not only bond angles but also relative lengths of bonds and sizes of atoms. 

The bond angles at the carbon atoms of ethane, and of all alkanes, are also tetrahedral like those in methane. A satisfactory model for ethane can be provided by ry) -hybridized carbon atoms. Figure 1.19 shows how we might imagine the bonding molecular orbitals of an ethane molecule being constructed from two ry) -hybridized carbon atoms and six hydrogen atoms. 

Methane (CH4) and ethane (C2He) are the first two members of the alkane family. Figure 3.2 shows molecular formulas, Lewis structures, and ball-and-stick models for these molecules. The shape of methane is tetrahedral, and all H—C—H bond angles are 109.5°. Each carbon atom in ethane is also tetrahedral, and all bond angles are... 

Experimental (dots) and theoretical (full line) molecular intensities of methane sulphonyl chloride. The difference curves refer to models differing mainly in the 0=S=0 bond angle ( 1, 120.8°, 2, 124.2°, and 5,127.5°)... 

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