The overall energy involved in the formation of CsCl from Cs(s) and Cl2(g) is −443 kJ/mol. Given the following information: heat of sublimation for Cs is +76 kJ/mol, bond dissociation energy for 12Cl2 is +121 kJ/mol, Ei1 for Cs is +376 kJ/mol, and Eea for Cl(g) is −349 kJ/mol. What is the magnitude of the lattice energy for CsCl?

Respuesta :

Answer :  The magnitude of the lattice energy for CsCl is, 667 KJ/mole

Explanation :

The steps involved in the born-Haber cycle for the formation of [tex]CsCl[/tex] :

(1) Conversion of solid calcium into gaseous cesium atoms.

[tex]Cs(s)\overset{\Delta H_s}\rightarrow Cs(g)[/tex]

[tex]\Delta H_s[/tex] = sublimation energy of calcium

(2) Conversion of gaseous cesium atoms into gaseous cesium ions.

[tex]Ca(g)\overset{\Delta H_I}\rightarrow Ca^{+1}(g)[/tex]

[tex]\Delta H_I[/tex] = ionization energy of calcium

(3) Conversion of molecular gaseous chlorine into gaseous chlorine atoms.

[tex]Cl_2(g)\overset{\frac{1}{2}\Delta H_D}\rightarrow Cl(g)[/tex]

[tex]\Delta H_D[/tex] = dissociation energy of chlorine

(4) Conversion of gaseous chlorine atoms into gaseous chlorine ions.

[tex]Cl(g)\overset{\Delta H_E}\rightarrow Cl^-(g)[/tex]

[tex]\Delta H_E[/tex] = electron affinity energy of chlorine

(5) Conversion of gaseous cations and gaseous anion into solid cesium chloride.

[tex]Cs^{1+}(g)+Cl^-(g)\overset{\Delta H_L}\rightarrow CsCl(s)[/tex]

[tex]\Delta H_L[/tex] = lattice energy of calcium chloride

To calculate the overall energy from the born-Haber cycle, the equation used will be:

[tex]\Delta H_f^o=\Delta H_s+\Delta H_I+\Delta H_D+\Delta H_E+\Delta H_L[/tex]

Now put all the given values in this equation, we get:

[tex]-443KJ/mole=76KJ/mole+376KJ/mole+121KJ/mole+(-349KJ/mole)+\Delta H_L[/tex]

[tex]\Delta H_L=-667KJ/mole[/tex]

The negative sign indicates that for exothermic reaction, the lattice energy will be negative.

Therefore, the magnitude of the lattice energy for CsCl is, 667 KJ/mole

The magnitude of  Lattice energy of CsCl is  -676 kJ/mol.

Given Here,

Enthalpy of sublimation of Cs  [tex]\rm \bold{ \Delta H(sub ) }[/tex] = +76 kJ/mo

Ionization Energy for Potassium  IE(Cs) = +376 kJ/mol

Electron affinity for Chlorine is EA(Cl)  =  −349 kJ/mol.

Bond dissociation energy of Chlorine, BE(Cl)  = +121 kJ/mol

Enthalpy of formation for CsCl,  [tex]\rm \bold{ \Delta H(f) }[/tex] =   −436.5 kj/mol .

The lattice energy of KCl can be calculated from the formula,

[tex]\rm \bold {U(CsCl) = \Delta Hf(CsCl) - [ \Delta H(sub) + IE(Cs) +BE(Cl_2) + EA(Cl)]}[/tex]

U( CsCl)  = -436 - [+76  +376   +121 kJ/mol  -349]

U( CsCl)  = -676 kJ/mol

Hence we can calculate that the magnitude of  Lattice energy of CsCl is  -676 kJ/mol.

To know more about Lattice Energy, refer to the link:

https://brainly.com/question/18222315?referrer=searchResults

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