Chapter 20, Problem 4A

Interpretation Introduction

Interpretation: The number of atoms bonded to each carbon atom in ethane and geometry around each atom in ethane needs to be determined.

Concept introduction: Hydrocarbon: A compound consisting only of hydrogen and carbon.

Answer to Problem 4A

Carbon is bonded with 3 hydrogen atoms and the geometry is tetrahedral.

Explanation of Solution

The reason so many carbon-containing compounds exist is because carbon forms strong bonds to itself and to many other elements. A carbon atom can form bonds to a maximum of four other atoms; these can be either carbon atoms or atoms of other elements.

The methane molecule consists of a carbon atom with four hydrogen atoms bound to it in a tetrahedral fashion. That is, as predicted by the VSEPR model, the four pairs of bonding electrons around the carbon have minimum repulsions when they are located at the corners of a tetrahedron.

The Lewis structure of ethane is Here the carbon is bonded with three hydrogen atoms and one carbon atom.

Conclusion

All alkanes can be represented by the general formula ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$ , where n represents the number of carbon atoms.