Calculate the net energy change in kilojoules per mole for the formation of KF(s) from the elements: K(s) + 1/2 F2(g) →KF(s). The following information is given: Heat of sublimation for K(s) = 89.2 kJ/mol,   Eea for F(g) = –328 kJ/mol Bond dissociation energy for F2(g) = 158 kJ/mol,   Ei for K(g) = 418.8 kJ/mol Electrostatic interactions in KF(s) = –821 kJ/mol

Lattice energies and electron affinities are very difficult to measure experimentally. Fairly reliable theoretical values for lattice energies can be calculated from simple models. The Born-Haber cycle can then be used to estimate electron affinities. Use the data below to calculate the electron affinity of iodine (in kJ mol-1), where a negative EA value indicates a favourable anion formation. Name of enthalpy change Value in kJ/mol Formation enthalpy of Cal 2(s) -533.46 Lattice energy of Cal2 -2074 Sublimation enthalpy of Ca 177.7 First ionization energy of Ca 589.8 Second ionization energy of Ca 1145.4 Sublimation enthalpy of I2 62.44 Bond energy of 12 151.1 -293 +265 -599 -482

Consider an ionic compound, MX₂, composed of generic metal M and generic, gaseous halogen X. • The enthalpy of formation of MX₂ is AH; = -905 kJ/mol. • The enthalpy of sublimation of M is AHsub = 111 kJ/mol. • The first and second ionization energies of M are IE₁ = 627 kJ/mol and IE₂ = 1362 kJ/mol. • The electron affinity of X is AHEA = -313 kJ/mol. (Refer to the hint). • The bond energy of X₂ is BE = 165 kJ/mol. Determine the lattice energy of MX₂. AH lattice = kJ/mol

Consider the following data for silver: atomic mass 107.87 g/mol electronegativity 1.93 electron affinity 125.6 kJ/mol ionization energy 731.0 kJ/mol heat of fusion 11.3 kJ/mol Does the following reaction absorb or release energy? (1) Ag(g) -> Ag+(g) + e- Is it possible to calculate the amount of energy absorbedor released by reaction (1) using only the data above? If you answered yes to the previous question, enter theamount of energy absorbed or released by reaction (1): Does the following reaction absorb or release energy? (2) Ag- (g) -> Ag(g) + e-  Is it possible to calculate the amount of energy absorbedor released by reaction (2) using only the data above? If you answered yes to the previous question, enter theamount of energy absorbed or released by reaction (2):