Now, the calcium cation and the chlorine anions are attracted by the electrostatic force of attraction and hence, there is the formation of an ionic bond between these two atoms. What is the lattice energy? 2nd Ionization Energy of Ca = 1145 $ kJ $ Bond Energy of Cl2 = 242.7 $ kJ $ Electron Affinity for chlorine = 2 $ \times $ (349 $ kJ $ ) Standard Enthalpy of Formation of CaCl2 (s) = 795 $ kJ $ We can substitute these values in the equation to find out the lattice energy Calculate the enthalpy of solution per mole of solid CaCl2. Chung (Peter) Chieh (Professor Emeritus, Chemistry @University of Waterloo). The Born-Haber cycle allows us to understand and determine the lattice energies of ionic solids. For example, we can find the lattice energy of CaO\text{CaO}CaO using the following information: Since we can find all of these energies experimentally, this is a surefire way of answering "What is the lattice energy of CaO\text{CaO}CaO?". Answer and Explanation: 1 Become a. It has ions with the largest charge. Such as in the song Jimmy by M.I.A look at aaja in the dictionary My indian boyfriend told me is meaning come to me, 6 Answers I have never had or heard of that particular brand, but have had several here in Canada, plus a number in the Caribbean and Asia, and there all the same, small cut hot dogs in a can, no need q now please.. Name the major nerves that serve the following body areas:? Lattice energy is equal to negative Q one times Q. The n values and the electronic configurations (e.c.) 2. D of Cl2 = 244 (Bond dissociation energy) How Calcium Chloride is an Ionic compound? Generally, calcium chloride is found in the hydrated form i.e., CaCl2 (H2O)n, where n = 0, 1, 2, 4, and 6. Experts are tested by Chegg as specialists in their subject area. 1999. erkki.kennesaw.edu/genchem8/ge00002.htm, Picture of NaCl diagram intro.chem.okstate.edu/1314f0BornHaber2.GIF. The bond energy of Cl2 is 242.6 kJ per mole of ClCl bonds. CaCO3 + 2NaCl CaCl2 + Na2CO3, Calcium chloride produces free calcium ions i.e., the aqua complex of calcium ion and chloride ion by dissolving themselves in water as follows, CaCl2 + 6H2O > [Ca(H2O)6]2+ + 2Cl. You'll get a detailed solution from a subject matter expert that helps you learn core concepts. The hydration enthalpy is the enthalpy change when 1 mole of gaseous ions dissolve in sufficient water to give an infinitely dilute solution. Socks Loss Index estimates the chance of losing a sock in the laundry. Madelung constants for a few more types of crystal structures are available from the Handbook Menu. Born-Land equation While the hard-sphere model is a useful approximation, it does have some issues. First, we can see that by increasing the charge of the ions, we will dramatically increase the lattice energy. IP of Na(g) = 496 (Ionization potential or energy) The other definition says that lattice energy is the reverse process, meaning it is the energy released when gaseous ions bind to form an ionic solid. The heat energy released when new bonds are made between the ions and water molecules is known as the hydration enthalpy of the ion. Hf of NaCl = -411 (Enthalpy of formation). (O) = -141 kJ/mol E.A. The Born-Haber cycle is more accurate as it is derived experimentally, but requires a larger amount of data. Atomisation : Ca (s) Ca (g) H 1 = + 121 KJ mol-1 . The diagram below is another representation of the Born-Haber Cycle. B)Enter the the Ksp expression forC2D3 in terms of the molar solubility x. Jimmy aaja -M.I.A. That immediately removes any possibility of confusion. Unfortunately, some of the factors for both the Born-Land and Born-Mayer equations require either careful computation or detailed structural knowledge of the crystal, which are not always easily available to us. For the reverse process of Equation \ref{eq1}: \[\ce{ a M^{b+} (g) + b X^{a-} (g) \rightarrow M_{a}L_{b}(s) }\]. The ground state electronic configuration of the calcium atom is [Ar] 4s2. Here, we need to provide a large amount of energy for the extraction of an electron from the 4s subshell as it is a filled subshell. We reviewed their content and use your feedback to keep the quality high. Ca (s) + Cl2 (g) CaCl2 (s) Hf0 = -795 KJ mol-1 Atomisation : Ca (s) Ca (g)H1 = + 121 KJ mol-1 Ionization : Ca (g) Ca2+ (g) + 2e-H2 = + 242.8 KJ mol-1 Dissociation : Cl2 (g) 2Cl (g) H3 = +242.8 KJ mol-1 The Lattice energy, \(U\), is the amount of energy required to separate a mole of the solid (s) into a gas (g) of its ions. Lattice Energy is used to explain the stability of ionic solids. For a quick review, the following is an example that illustrate the estimate of the energy of crystallization of NaCl. It is this that causes ionic solids to have such high melting and boiling points. Before we get to grips with finding the lattice energy, it's important to know the lattice energy definition as it is quite peculiar. The Born-Haber Cycle requires that the elements involved in the reaction are in their gaseous forms. How is lattice energy estimated using Born-Haber cycle? Calculate the pH of a solution of 0.157 M pyridine. kJ/mol CaCl2 Submit Submit Answer Try Another Version 9 item attempts remaining. These additional reactions change the total energy in the system, making finding what is the lattice energy directly difficult. Lattice Energy: The Born-Haber cycle is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by LibreTexts. Reference for second table (theoretical and BHFC values) is. The lattice energy of Calcium chloride CaCl 2 is - 2195. Lattice energy depends on two important factors. This will cause a release of energy, which is called the lattice energy. Some require such high temperatures that they decompose before they can reach a melting and/or boiling point. Techiescientist is a Science Blog for students, parents, and teachers. The Madelung constant, \(M\), is a poorly converging series of interaction energies: \[ M= \dfrac{6}{1} - \dfrac{12}{2} + \dfrac{8}{3} - \dfrac{6}{4} + \dfrac{24}{5} \label{6.13.2}\]. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. In this bond order calculator we will show you how to find the bond order using Lewis structures, or a formula derived from the molecular orbital theory. Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. Oxford: Clarendon Press, 1992. Usually, the second ionization energy is greater than the first ionization energy. Therefore, option (c) is correct. MgO. Dr. Leon L. Combs. CaCl2, referred to as calcium chloride, is a member of alkaline earth metal halides i.e., MX2, where, M is an alkaline earth metal. 2*Cl(g) + 2e -->2*Cl^-(g) dH =2*-348 kJ Does MgCl2 have a high lattice energy? A chemical bond is an Ionic bond if the electronegativity difference of the chemical bond is greater than 2.0 and it will be a covalent bond if the electronegativity difference is less than 2.0 on the Pauling scale. In other words, treating the AgCl as 100% ionic underestimates its lattice enthalpy by quite a lot. It is, however, still an approximation, and improvements to the repulsion term have since been made. After the removal of an electron, the electronic configuration of the unipositive calcium ion becomes [Ar] 4s1. kJ/mol CaCl2 Submit Submit Answer Try Another Version 9 item attempts remaining This problem has been solved! This is the energy of the ionic solid, and will be used at the end of the process to determine the lattice energy. Skill:Explain the trend of lattice energy. Ca2+(g) +2e- +2Cl(g) (up arrow) enthalpy ionisation down arrow electron affinity Ca+(g) + e- +2Cl(g) Ca2+(g) +2Cl-(g) (up arrow) enthalpy ionisation down arrow lattice enthalpy Ca(g) +2Cl(g) (up arrow) enthalpy atomisation Ca(g) +Cl2(g) (up arrow) enthalpy atomisation Ca (s) +Cl2(g) down arrow) enthalpy formation CaCl2(S) Lattice enthalpy = enthalpy formation enthalpy atomisation for calcium 2x enthalpy atomisation for chlorine-1st and second ionisation energies for calcium electron affinity for Clx2, Your email address will not be published. Calcium chloride has cation Ca 2 + and two anions of Chlorine Cl -. This definition causes the value for the lattice energy to always be positive, since this will always be an endothermic reaction. This has led many people to look for a theoretical way of finding the lattice energy of a compound. Boston: Birkhauser, 2005. KF MgS RbI Is there a formula or some simple way of knowing which has the greatest energy? The Kb of pyridine, C5H5N, is 1.5 x 10-9. Mi hermana se sorprende N-F C-F Cl-F F-F 2 Answers C-F is the most polar. ---------------------------------- The melting and boiling point of anhydrous calcium chloride is very high. Evaluate the energy of crystallization, Ecryst for CaO. Because there is actually some element of repulsion between the anion and cation, the hard-sphere model tends to over-estimate the lattice energy. Hence, ionic bond results when there is transferring of electron (s) either from one atom to another atom or from metal to nonmetal. Which one of the following has the largest lattice energy? document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Welcome to Techiescientist.com. However, the melting point of hexahydrate calcium chloride is only 29.9 C. My aim is to uncover unknown scientific facts and sharing my findings with everyone who has an interest in Science. The solids consists of divalent ions have much larger lattice energies than solids with monovalent ions. Ca(g) --> Ca^+ + e dH = + 589.5 kJ Calculate the pH of a solution of 0.157 M pyridine.? Unfortunately, this is not the case. Calculate the lattice enthalpy of CaCl 2, given that :Enthalpy of sublimation for Ca s Ca g =121 kJ mol 1Enthalpy of dissociation of Cl 2 g 2 Cl g =242.8 kJ mol 1Ionisation energy of Ca g Ca ++ g =2422 kJ mol 1Electron gain enthalpy of 2 Cl 2 Cl 1 =2 355 kJ mol 1= 710 kJ mol 1Enthalpy of formation of CaCl 2= 795 kJ mol 1A. The lattice energy (U) of the calcium chloride is -2195 kJ/mol. Permalink is the link containing your input data. Thus, the energy due to one ion is, \[ E = \dfrac{Z^2e^2}{4\pi\epsilon_or} M \label{6.13.1}\]. First equal the formation enthalpy to the sum of all the other enthalpy's and use letter X to represent the lattice enthalpy . This is permalink. Perhaps surprisingly, there are several ways of finding the lattice energy of a compound. The positive ions experience both attraction and repulson from ions of opposite charge and ions of the same charge. Ca^2+(g) + 2Cl^-(g) --> CaCl2 dH = lattice A is the number of anions coordinated to cation and C is the numbers of cations coordinated to anion. Lime, CaO, is know to have the same structure as NaCl and the edge length of the unit cell for CaO is 481 pm. The value calculated for U depends on the data used. "Lattice Energy". EA of Cl(g) = -349 (Electron affinity of Cl) Spanish Help plz tell me what are the steps to solve this question. They are: 1. It can also be calculated from the electrostatic consideration of its crystal structure. In this simple view, appropriate number of cations and anions come together to form a solid. However, many nonmetals will exist as polyatomic species. In India on the occasion of marriages the fireworks class 12 chemistry JEE_Main, The alkaline earth metals Ba Sr Ca and Mg may be arranged class 12 chemistry JEE_Main, Which of the following has the highest electrode potential class 12 chemistry JEE_Main, Which of the following is a true peroxide A rmSrmOrm2 class 12 chemistry JEE_Main, Which element possesses the biggest atomic radii A class 11 chemistry JEE_Main, Phosphine is obtained from the following ore A Calcium class 12 chemistry JEE_Main, Differentiate between the Western and the Eastern class 9 social science CBSE, NEET Repeater 2023 - Aakrosh 1 Year Course, CBSE Previous Year Question Paper for Class 10, CBSE Previous Year Question Paper for Class 12. The basis of these models are, One of most common crystal model is so-called, Data within first table (ion pairs) come from. El subjuntivo It is hygroscopic in nature and hence, used in the desiccators for drying chemicals. { "00:_Front_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", Lattice_Energy : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Lattice_Energy:_The_Born-Haber_cycle" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", Lattice_Enthalpies_and_Born_Haber_Cycles : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "The_Born-Lande\'_equation" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "zz:_Back_Matter" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { Inorganic_Solids : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", Lattice_Basics : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", Lattice_Defects : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", Metal_Lattices : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", Solids : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", Thermodynamics_of_Lattices : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, [ "article:topic", "Born-Haber cycle", "showtoc:no", "license:ccbyncsa", "licenseversion:40" ], https://chem.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fchem.libretexts.org%2FBookshelves%2FInorganic_Chemistry%2FSupplemental_Modules_and_Websites_(Inorganic_Chemistry)%2FCrystal_Lattices%2FThermodynamics_of_Lattices%2FLattice_Energy%253A_The_Born-Haber_cycle, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), status page at https://status.libretexts.org. The ionization energy of M is IE = 433 kJ/mol. The energy to break 1 mole of a lattice at the standard temperature and pressure is defined as the standard lattice energy. Required fields are marked *. Corrundum Al2O3 has some covalent character in the solid as well as the higher charge of the ions. As the ionic radii of either the cation or anion increase, the lattice energies decrease. Ea for F = -328 E11 forCs = +375.7 E12 for Cs = +2422 Heat of sublimation for Cs =, Na+(g) + Br-(g) --> NaBr (s) Hint: use the Born-Haber cycle Note: the reference state for Br2 is Br2(l) not Br2(g) Data (in kJ/mol): enthalpy of sublimation of Na(s): 107 standard enthalpy, I have to place the following in order of decreasing magnitude of lattice energy, but I don't know how to do it. For these reasons they have not been included in the present lattice energy calculator. LiCl, NaCl, CaCl2, Al2O3. Lattice Energy is Related to Crystal Structure, status page at https://status.libretexts.org. 2003-2023 Chegg Inc. All rights reserved. You're probably well aware of how ubiquitous ionic lattices are - you'll find them in your food, medicine, and maybe even in the walls of your house - but by learning what lattice energy is, the lattice energy formula, and the lattice energy trend, your appreciation for chemistry will surely increase. Why is my internet redirecting to gslbeacon.ligit.com and how do I STOP THIS. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. --------------------------------------------------------------------------------------------------------------------------------------------. The Kb of pyridine, C5H5N, is 1.5 x 10-9. Thus, Ca-O distance is 241 pm. Study with Quizlet and memorize flashcards containing terms like Beryllium forms a compound with chlorine that has the empirical formula BeCl2. Hence, calcium chloride is an ionic compound. Im a mother of two crazy kids and a science lover with a passion for sharing the wonders of our universe. To correct for this, Born and Land (yes, the same Born as in the Born-Haber cycle, prolific, we know) proposed an equation to describe this repulsive energy: By adding this correction to the hard-sphere equation, differentiating it with respect to rrr, assuming that at r=r0r=r_0r=r0 the potential energy is at a minimum, rearranging for BBB, and finally substituting that back into the hard-sphere equation, you end up with the Born-Land equation: As you might expect, the Born-Land equation gives a better prediction of the lattice energy than the hard-sphere model. Calculate the lattice energy of Cacl2 given that the heat of sublimation of Ca=121 kJ/mol and Hf Cacl2=-795 first ionization of ca = 589.5 second ionization of ca = 1145 the electron affinity of Cl = 349 the cl2 bond energy is 242.7 I have found all information that i believe are needed to Evaluate the energy of crystallization, Ecryst . Lattice energy is often used to estimate the strength of an ionic bond. Journal of Chemical Education. Ionic solids tend to be very stable compounds. Two over R. And lattice energy. 11 Uses of Platinum Laboratory, Commercial, and Miscellaneous, CH3Br Lewis Structure, Geometry, Hybridization, and Polarity. Diaphragm _____ 3. Express your answer in terms of x. as compared to the calcium atom. of the corresponding inert gases are given below: The following values of n have been suggested for some common solids: Estimate the energy of crystallization for \(\ce{NaCl}\). Ladd, Mark. Both the salts have common anion Cl-. Find more about crystallography with our cubic cell calculator! A highly concentrated solution of calcium chloride on the road prevents the formation of the dust owing to its hygroscopic nature and forming a liquid layer on the surface of the road. Hence, a covalent bond may be polar or nonpolar. Combs, Leon. [References) CHEMWORK The lattice energy of CaCl, is-2247 kJ/mol, and the enthalpy of hydration of one mole of gaseous Ca2+ and two moles of gaseous Cl" ions is -2293 kJ/mol. For a single atom in the lattice, the summation of all of these interactions can be found, known as the Madelung constant, MMM, which is then multiplied by the equation above. Calculate the lattice energy of CaCl2 from the given data, \[\ce{Ca_{(s)} + Cl2_{(g)} -> CaCl2_{(s)}}\] `"H"_"f"^0` = 795 kJ mol1, Sublimation: \[\ce{Ca_{(s)} -> Ca-{(g)}}\] `"H"_1^0` = + 121 kJ mol1, Ionisation: \[\ce{Ca_{(g)} -> Ca^2+_{(g)} + 2e^-}\] `"H"_2^0` = + 2422 kJ mol1, Dissociation: \[\ce{Cl2_{(g)} -> 2Cl_{(g)}}\] `"H"_3^0` = + 242.8 kJ mol1, Electron affinity: \[\ce{Cl_{(g)} + e^- -> Cl^-_{(g)}}\] `"H"_4^0` = 355 kJ mol1, 795 = 121 + 2422 + 242.8 + (2 355) + u, Chapter 7: Thermodynamics - Evaluation [Page 226], Tamil Nadu Board Samacheer Kalvi Class 11th Chemistry Volume 1 and 2 Answers Guide, Maharashtra Board Question Bank with Solutions (Official), Mumbai University Engineering Study Material, CBSE Previous Year Question Paper With Solution for Class 12 Arts, CBSE Previous Year Question Paper With Solution for Class 12 Commerce, CBSE Previous Year Question Paper With Solution for Class 12 Science, CBSE Previous Year Question Paper With Solution for Class 10, Maharashtra State Board Previous Year Question Paper With Solution for Class 12 Arts, Maharashtra State Board Previous Year Question Paper With Solution for Class 12 Commerce, Maharashtra State Board Previous Year Question Paper With Solution for Class 12 Science, Maharashtra State Board Previous Year Question Paper With Solution for Class 10, CISCE ICSE / ISC Board Previous Year Question Paper With Solution for Class 12 Arts, CISCE ICSE / ISC Board Previous Year Question Paper With Solution for Class 12 Commerce, CISCE ICSE / ISC Board Previous Year Question Paper With Solution for Class 12 Science, CISCE ICSE / ISC Board Previous Year Question Paper With Solution for Class 10, HSC Science Class 11th Tamil Nadu Board of Secondary Education. Calculate the lattice energy for CaCl2 from the following information: Energy needed to vaporize one mole of Ca(s) is 192kJ. Energy of crystallization is -3527 kJ/mol. 4. There are several important concept to understand before the Born-Haber Cycle can be applied to determine the lattice energy of an ionic solid; ionization energy, electron affinity, dissociation energy, sublimation energy, heat of formation, and Hess's Law. Anhydrous calcium chloride crystallizes in the orthorhombic and tetragonal structure whereas hexahydrate calcium chloride crystallizes itself in trigonal structure. Ca^+(g) --> Ca^2+ + e dH = + 1146 kJ When methods to evaluate the energy of crystallization or lattice energy lead to reliable values, these values can be used in the Born-Haber cycle to evaluate other chemical properties, for example the electron affinity, which is really difficult to determine directly by experiment. It is subtracted because it is a release of energy associated with the addition of an electron. In the case of the calcium chloride compound (CaCl2), The electronegativity value of the calcium atom = 1.0, The electronegativity value of the chlorine atom = 3.16, The electronegativity difference of the Ca-Cl bond = 2.16. Solid State Chemistry. the energy released is called energy of crystallization (\(E_{cryst}\)). Looking at the Kapustinskii equation above, we can begin to understand some of the lattice energy trends as we move across and down the periodic table. The atomic mass calculator takes the number of protons and neutrons in an atom and displays the atomic mass in atomic mass units and kilograms. It is an inorganic . This can be thought of in terms of the lattice energy of NaCl\text{NaCl}NaCl: That the ions are in their gaseous state is important; in this form, they are thought to be infinitely far apart, i.e., there are no interactions between them. Born-Haber Cycle As one might expect, the best way of finding the energy of a lattice is to take an amount of the substance, seal it in an insulated vessel (to prevent energy exchange with the surroundings), and then heat the vessel until all of the substance is gas. As implied in the definition, this process will always be exothermic, and thus the value for lattice energy will be negative. Calculate the lattice enegry of CaCl2 from the given data. Hydration enthalpies are always negative. Some might expect such an ordered structure to be less stable because the entropy of the system would be low. Much more should be considered in order to evaluate the lattice energy accurately, but the above calculation leads you to a good start. You can calculate the last four using this lattice energy calculator. The lattice energy (U) of the calcium chloride is . Values of lattice energies for various solids have been given in literature, especially for some common solids. This has been going on for about a week Every time I try to watch a video on Youtube from my laptop I get instantly redirected to "gslbeacon.ligit.com." The bond energy of Cl2 is 242.6kJ/mol of CI-Cl bonds. Which one of the following has the greatest lattice energy? Calculate the lattice energy of CaCl 2 using a Born-Haber cycle and data from Appendices F and L and Table 7.5. Name the major nerves that serve the following body areas? Seattle, Washington(WA), 98106. The nearest neighbors of Na+ are 6 Cl- ions at a distance 1r, 12 Na+ ions at a distance 2r, 8 Cl- at 3r, 6 Na+ at 4r, 24 Na+ at 5r, and so on.