If (2Z,4Z)-hexa-2,4-diene were able to undergo a Diels–Alder reaction with methyl propenoate, what would be the products? (Hint: There are four products comprised of two pairs of enantiomers. One enantiomer pair would predominate.) In reality, this Diels–Alder reaction is impractical because the s-cis conformation of the diene required for the reaction is of high energy due to steric hindrance between the methyl groups.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.

hypostyle hall;