A three dimensional representation of butane is shown on the left. Translate the information about the conformation of butane into its Newman projection on the right, and determine if this conformation represents a local energy minimum or a global energy minimum.

Explanation:

The rotation of the image depicts the anti-conformation of butane which is a global energy at lowest level for the molecule which doubles methyl group equal to 180°, this generates steric repulsion at the least quantity.

* A diagram is attached

The diagram is in the attachment below. The Newman projection illustration of butane

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.