What is the largest alkane (number of carbons) that can be named not exceeding “decane” as a parent? Where is the primary How many What family. I.e. what Where and what carbons? Is the primary functional group? Are the substituents? Functional group? Torsional strain (excess energy in the non-staggered conformations) is due to increased CH bonding electron repulsion. The “extra” energy of some conformations due to less than optimal molecular geometry, can be accounted by torsional and steric strain. (Other compounds may also have angle strain.) What is the minimum energy difference between the “straight” and once “bent” chain?