Ethane, bond angles molecular model

Practice working with your Learning By Modeling software Construct molecular models of ethane ethylene and acetylene and compare them with respect to their geometry bond angles and C—H and C—C bond distances... 

Make molecular models of ethane and ethene. Notice the tetrahedral shape and 109° bond angles around each carbon of ethane and the trigonal shape and 120° bond angles around each carbon of ethene. Also notice that you can rotate the single bond of ethane but not the double bond of ethene. 

All calculations are based on mechanical molecular models the atoms are more or less deformable spheres, the bonds are rigid springs. Attraction and repulsion are calculated separately as a function of the torsion angle. A typical exercise, for example, proceeds from the total energy of an ethane molecule, which is made up of five components (Figure 4-4) ... 

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... 

Three-dimensional models of ethane, propane, and butane. The ball-and-stick models at the left show the way in which the atoms are connected and depict the correct bond angles. The spacefilling models at the right are constructed to scale and give a better idea of the molecular shape, though some of the hydrogens may appear hidden. 

Molecular models and Newman projections of the staggered and eclipsed conformations of ethane. The dihedral angle in the staggered form is 60T and that in the eclipsed form is 0°. The C—C bond is rotated slightly in the Newman projection of the eclipsed form in order to show the H atoms attached to the back C atom. 

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