Chemistry - GOC Question with Solution | TestHub

(1) diene C=C-C=C, (2) ene-yne $\mathrm{C}\equiv \mathrm{C}-\mathrm{C}=\mathrm{C}$ and (4) 1,3-cyclohexadiene are conjugated.

In (3) and (5) the two $\mathrm{C}=\mathrm{C}$ are separated by $\mathrm{s}{\mathrm{p}}^3$ carbons. Count = 3.