Which of the following represents the correct decreasing order of the magnitude of heat of hydrogenation for the given dienes? (i) (ii) (iii) (iv)

Step-by-step solution

To determine the correct decreasing order of the magnitude of heat of hydrogenation, we need to evaluate the stability of the given dienes. The heat of hydrogenation is inversely proportional to the stability of the alkene. Let us identify the structure of each diene from the given images: 1. (i) is trans,trans -2,4-hexadiene. It is a conjugated diene with two alkyl substituents on the diene system. 2. (ii) is 1,4-hexadiene. It is an isolated diene (the double bonds are separated by an sp^3 hybridized carbon). 3. (