(i) Excluding the C3−C4 bond of 2,5-dimethylhexane, about which other C−C bonds can rotation take place?



(ii) Determine the number of the C−C bonds in 2,5-dimethylhexane that have equally stable staggered conformers.

• A. (i): C1−C2 bond, C2−C3 bond, C2−C7 bond, C4−C5 bond, C5−C6 bond, and C5−C8 bond.
  (ii): 4
• B. (i): C1−C2 bond, C2−C3 bond, C2−C7 bond, C4−C5 bond, C5−C6 bond, and C5−C8 bond.
  (ii): 7
• C. (i): C2−C3 bond and C4−C5 bond.
  (ii): 4
• D. (i): C2−C3 bond and C4−C5 bond.
  (ii): 7

Answer: (A)