(a)
Interpretation:
The two-particle coulombic energy of attraction is to be compared with more precise calculation of the lattice energy for the given ionic crystal.
Concept introduction:
The amount of energy released when one formula unit moles of oppositely charged gaseous ions binds together to form a crystal is known as the lattice energy. The value of lattice energy is negative. It is used as a measure for stability of a crystal.
Answer to Problem 21.52E
The two-particle coulombic energy of attraction is
Explanation of Solution
According to Coulomb’s law the potential energy of two oppositely charged particles that are
Where,
•
•
The closed distance between the opposite ions is calculated by considering the Table 21.4. The radii of
Thus, the closest distance between the opposite ions is
Substitute the values of charge on electron, permittivity of space and distance between two ions in equation (1).
For one mole of ions, the energy is multiplied by Avogadro number as shown below.
Thus, the two-particle coulombic energy of attraction is
The lattice energy is given by the expression as shown below.
Where,
•
•
•
•
•
•
•
From the Table 21.6, the value of
The
Substitute value of
Thus, the calculated lattice energy is
Therefore, the magnitude of two-particle coulombic energy of attraction is less than the lattice energy.
The two-particle coulombic energy of attraction is
(b)
Interpretation:
The two-particle coulombic energy of attraction is to be compared with more precise calculation of the lattice energy for the given ionic crystal.
Concept introduction:
The amount of energy released when one formula unit moles of oppositely charged gaseous ions binds together to form a crystal is known as the Lattice energy. The value of lattice energy is negative. It is used as the measure for stability of a crystal.
Answer to Problem 21.52E
The two-particle coulombic energy of attraction is
Explanation of Solution
According to Coulomb’s law the potential energy of two oppositely charged particles that are
Where,
•
•
The closed distance between the opposite ions is calculated by considering the Table 21.4. The radii of
Thus, the closest distance between the opposite ions is
Substitute the values of charge on electron, permittivity of space and distance between two ions in equation (1).
For one mole of ions, the energy is multiplied by Avogadro number as shown below.
Thus, the two-particle coulombic energy of attraction is
The lattice energy is given by the expression as shown below.
Where,
•
•
•
•
•
•
•
From the Table 21.6, the value of
Substitute value of
Thus, the calculated lattice energy is
Therefore, the magnitude of two-particle coulombic energy of attraction is less than the lattice energy.
The two-particle coulombic energy of attraction is
(c)
Interpretation:
The two-particle coulombic energy of attraction is to be compared with more precise calculation of the lattice energy for the given ionic crystal.
Concept introduction:
The amount of energy released when one formula unit moles of oppositely charged gaseous ions binds together to form a crystal is known as the Lattice energy. The value of lattice energy is negative. It is used as the measure for stability of a crystal.
Answer to Problem 21.52E
The two-particle coulombic energy of attraction is
Explanation of Solution
According to Coulomb’s law the potential energy of two oppositely charged particles that are
Where,
•
•
The closed distance between the opposite ions is calculated by considering the Table 21.4. The radii of
Thus, the closest distance between the opposite ions is
Substitute the values of charge on electron, permittivity of space and distance between two ions in equation (1).
For one mole of ions, the energy is multiplied by Avogadro number as shown below.
Thus, the two-particle coulombic energy of attraction is
The lattice energy is given by the expression as shown below.
Where,
•
•
•
•
•
•
•
From the Table 21.6, the value of
Substitute value of
Thus, the calculated lattice energy is
Therefore, the magnitude of two-particle coulombic energy of attraction is less than the lattice energy.
The two-particle coulombic energy of attraction is
Want to see more full solutions like this?
Chapter 21 Solutions
Physical Chemistry
- Use a Born-Haber cycle (Sec. 5-13) to calculate the lattice energy of MgF2 using these thermodynamic data. Compare this lattice energy with that of SrF2, −2496 kJ/mol. Explain the difference in the values in structural terms.arrow_forwardThe standard enthalpies of formation for S(g), F(g), SF4(g), and SF6(g) are +278.8, +79.0, 775, and +1209 KJ/mol, respectively. a. Use these data to estimate the energy of an SF bond. b. Compare your calculated value to the value given in Table 3-3. What conclusions can you draw? c. Why are the Hf values for S(g) and F(g) not equal to zero, since sulfur and fluorine are elements?arrow_forwardGiven the following data calculate H for the reaction On the basis of the enthalpy change, is this a useful reaction for the synthesis of ammonia?arrow_forward
- The reaction of quicklime, CaO, with water produces slaked lime, Ca(OH)2, which is widely used in the construction industry to make mortar and plaster. The reaction of quicklime and water is highly exothermic: CaO(s)+H2O(l)Ca(OH)2(s)H=350kJmol1 (a) What is the enthalpy of reaction per gram of quicklime that reacts?. (b) How much heat, in kilojoules, is associated with the production of 1 ton of slaked lime?arrow_forwardThe bond energy for a CH bond is about 413 kJ/mol in CH4 but 380 kJ/mol in CHBr3. Although these values are relatively close in magnitude, they are different. Explain why they are different. Does the fact that the bond energy is lower in CHBr3, make any sense? Why?arrow_forwardWhen boron hydrides burn in air, the reactions are very exothermic (a) Write a balanced equation for the combustion of B5H9(g) in air to give B2O3(s) and H2O(g). (b) Calculate the enthalpy of combustion for B5H9(g) (fH = 73.2 kJ/mol), and compare it with the enthalpy of combustion of B2H6 (2038 kJ/mol). (The enthalpy of formation of B2O3(s) is 1271.9 kJ/mol.) (c) Compare the enthalpy of combustion of C2H6(g) with that of B2H6(g). Which transfers more energy as heat per gram?arrow_forward
- The attractive force between a pair of Sr2+ and O2- ions is 1.52 x 108 N and the ionic radius of O2- ions is 0.134 nm. Calculate the ionic radius of the Sr2+ ion. (Given: Electron charge, e = 1.6 x 101ºC, the permittivity of free space, Eo = 8.85 x 101ºC²N'm²)arrow_forwardGiven the following data, calculate the lattice energy of barium chloride, BaCl. IE 1BA= 502.7 kJ mol, IE 2Ba = 965.0 kJ mol, AHsub (Ba) =175.6 kJ moľ, EA = 349.0 kJ mol, BDE (CI - CI) = 243.4 kJ mol, AH(BaCl) = -858.6 kJ molarrow_forwardUse the Born Haber cycle (show relevant steps) to determine the lattice energy of CsCl (s) from the following data:Hf 0 [CsCl(s)] = -442.8 kJ/mol; enthalpy of sublimation of Cesium is 78.2 kJ/mol; enthalpy of dissociation of Cl2 (g) = 243 kJ/mol Cl2 ; IE1 for Cs(g) = 375.7 kJ/mol; electron affinity enthalpy-EA1 for Cl(g) = -349kJ/molarrow_forward
- 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 = ?arrow_forwardDetermine the crystal lattice energy for MgCl2, given the following information: Cl2(g) → Mgčl2(s)AH°f = -642 kJ/mol 2+ (Mg - AHvaporization = 147.7 kJ/mol, Mg- Ejionization = 2188.4 kl/mol, Cl2 - EBond = 248 kJ/mol, Cl" - Ejonization = -349 kJ/mol)arrow_forwardCalculate the lattice energy,U (in kJ), of the fictitious compound, MCl2, given the following information: ΔHppt for MCl2 = 17.1 kJ/mol, ΔHhyd for M2+ = -450 kJ/mol, ΔHhyd for Cl- = -370 kJ/mol Your answer should have 4 sig figs.arrow_forward
- Physical ChemistryChemistryISBN:9781133958437Author:Ball, David W. (david Warren), BAER, TomasPublisher:Wadsworth Cengage Learning,Chemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
- Chemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry by OpenStax (2015-05-04)ChemistryISBN:9781938168390Author:Klaus Theopold, Richard H Langley, Paul Flowers, William R. Robinson, Mark BlaserPublisher:OpenStaxChemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning