in order to build a new dock at the lake place, you require fasteners like the one
shown. at stoich's hardware, you find that you are able to purchase bolts
in packages of three for 59¢, nuts in packages of 11 for 49¢ and washers in
packages of 23 for 49¢.
a. describe the construction of the desired fasteners using symbols
(as in a chemical equation) rather than words.

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.