The rate of a chemical reaction varies, depending on the initial amount of a certain compound. In general, the reaction rate, V, can be expressed by the following formula, where k is a positive constant, and a is the initial amount of the compound. V(x)equalskx(aminusx) The positive constant, k, for one such reaction is 0.4, and the initial amount of the compound, a, is 22. For what value of x is the rate a maximum?

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.

56 moles of   lieter in chemistry