Question

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 ½ Cl2is +121 kj/mol,
•E(11) for Cs is +376 kj/mol, and
•E(a) for Cl2is 349 kj/mol.

what is the magnitude of the lattice energy for CsCl?
in kj/mol




attempted
i guess the formula we ahve to use is
U= k ( z1 x z2)/ d

but i don't knw which is which

so plz can someone
need help badly
someone can plz solveit for me

thnks

ybe

Answer 1

What is E(11)? Is that the ionization potential of Cs gas to Cs^+ + e?

Answer 2

That 376 sounds high for the ionization potential. Also, did you make a typo on the Ea for Cl. I think that should be -349 (or at least the number should be negative). I don't know if the number is correct or not.

Answer 3

Assuming E(11) is the ionization potential for Cs(g) ==> Cs^+ +e
then
Sublimation + ionization + 1/2 dissociation + electron affinity + Ecrystallization = heat formation.


If your numbers are right, then 76+376+121-349+Ecrystallization = -443. Solve for E crystal.
Most P. Chem texts I've seen define U as crystal lattice energy = - E crystal.
Solve for E crystallization. E crystal should be a negative number

Answer 4

U=(-443-76-121-376+349)
=-667