a) * Các CTCT của ankin có CTPT C4H6 là:

But-1-in: CH≡C−CH2−CH3CH≡C-CH2-CH3

But-2-in: CH3−C≡C−CH3CH3-C≡C-CH3

    *  Các CTCT của ankin có CTPT C5H8 là: 

Pent-1-in: CH≡C−CH2−CH2−CH3CH≡C-CH2-CH2-CH3

Pent-2-in: CH3−C≡C−CH2−CH3CH3-C≡C-CH2-CH3

3-metylbut-1-in: CH≡C−CH−CH3                  /                 CH3CH≡C-CH-CH3                  /                 CH3

b)

pent-2-in: CH3−C≡C−CH2−CH3CH3-C≡C-CH2-CH3

3-metylpent-1-in: CH≡C−CH−CH2−CH3                  /                 CH3CH≡C-CH-CH2-CH3                  /                 CH3

2,5- đimetylhex-3-in: CH3−CH−CH≡C−CH−CH3          /                         /        CH3                    CH3CH3-CH-CH≡C-CH-CH3          /                         /        CH3                    CH3