A) do you need a soluble salt from an acid in titration b) do you need an insoluble base in titration
c) what does titration make sure the reactants produce?

Titration must be used to obtain a solution of a salt and water only, when using an acid and an alkali. This is because there is no insoluble excess reactant that could be removed by filtration .

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.

c, liquids evaporate, creating a gas