To explain why AHan for RbCl is different than that for KCI, the student investigates factors that affect AHoln and finds that ionic radius and lattice enthalpy (which can be defined as the AH associated with the separation of a solid crystal into gaseous ions) contribute to the process. The students consults references and collects the data shown in the table below. lonic Radius (pm) lon к' 138 Rb* 152 b. Using principles of atomic structure, explain why the Rb' ion is larger than the K' ion

The energy for the following reaction was measured to be -653.0 kJ/mol. K(g) + Cl(g) →→KCI(s). Using this fact and the data in the table below, calculate the enthalpy (in kJ/mol) required to separate the ions from the lattice for this reaction: KCI(s) → K+(g) + Cl-(g). Substance K (g) CI (g) Ionization Energies (kJ/mol) 418.8 1251.1 Electron Affinities (kJ/mol) -48.384 -349

3. In general, as you go down a column in the periodic table, will the interaction between the nucleus and valence electrons get stronger or weaker? Explain. While you can simply memorize all the different periodic trends, many can be understood in terms of the two competing factors in Coulombs law ( Zeff vs. distance, r).

Combine two elements (cesium, berryllium, bromine, and flourine) from the following: ( K, Mg, Mn, N, O, Fe, Cu, H, S, Kr,C, Na, Br, Cl) to form 5 different molecules, including one oxy atomic moleculeand one diatomic molecule from the given elements(cesium, berryllium, bromine, and flourine), and determine the following: a) the electronegativity of the compound (show your calculation)  b) Is the selected molecule polar, or not? What type of bond is formed based onwhat you learned? Is it a strong or weak bond?

based on the following information calculate the approximate lattice energy of XCl2.X is 3x larger than Na+. The lattice energy for NaCl is 787kj/mole

The electron configuration of an element, X, is [Ne] 3s¹. The formula of the most probable ionic compound that this element will form with Br is Note: The compound Fe(CIO4)3 should be entered as "Fe(CIO4)3".

1. Below is a list of enthalpy changes for the Born-Haber cycle for the formation of solid LiF from Li(s) and F(g). Use these data to determine the lattice energy for the formation LiF(s). Li(s) → Li(g)       ΔH1 = +162 kJ/mol Li(g) → Li+(g) + e-     ΔH2  = +520.2 kJ/molF2(g) → 2F(g)     ΔH3  = 154 kJ/mol F(g) + e-  →  F-(g)     ΔH4  = -328 kJ/molLi(s) +  1/2F2(g) → LiF(s)   ΔHf = -612 kJ/mol Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a. 1371 kJ/mol b. -1371 kJ/mol c. 1043 kJ/mol d. -1043 kJ/mol

d. The energy required to separate the ions in the calcium carbonate crystal lattice into individual calcium and carbonate ions as represented in the table below is known as the lattice energy. As shown in the table, the lattice energy of magnesium carbonate is more than the lattice energy of calcium carbonate. Explain why in terms of periodic properties and Coulomb's law.

The lattice energy of magnesium sulfide is the energy change accompanying the process Mg2*(g) + + S2-(g) → MgS(s) Calculate the lattice energy of MgS using the following data: Mg(s) → Mg(g) AH° = 148 kJ/mol Mg(g) → Mg2*(g) + 2e- AH° = 2186 kJ/mol Sg(s) → 8S(g) AH° = 2232 kJ/mol S(g) + 2e-- s2-(g) AH° = 450 kJ/mol 8Mg(s) + Sg(s) → 8MGS(s) AH° = -2744 kJ/mol Mg2*(g) + S2-(g)→ MgS(s) AH°lattice = ?

Place the following elements in... increasing electronegativity:    Se  Cl  S increasing ionization energy:  Al  P  Sr increasing affinity for electrons: K  Ge  Cl increasing lattice energy: Na2S  KCl  MgS