Question

Eclipsed conformation of ethane is destabilized by​

Answer 1

Answer: torsional strain

Answer 2

In CH3-NH2 the eclipsed conformation is about 1.98 kcal/mol above the staggered conformation, and in CH3-OH the eclipsed conformation is about 1.07 kcal/mol above the staggered conformation, so these results broadly agree with the “1 kcal/mol per eclipsing C-H bond” result.