Which statement about crystal lattice energy is best supported by the information in the table?

a. the lattice energy increases as cations get smaller, as shown by lif and kf.

b. the lattice energy increases as the charge of anions increases, as shown by lif and licl.

c. the lattice energy decreases as anions get smaller, as shown by nacl and naf.

d. the lattice energy decreases as the charge of cations decreases, as shown by naf and kf.

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.