The estimated lattice energy for is CsF2+2347kj/mol. Use the data given to calculate an overall energy change (in kilojoules per mole) for the formation of from its elements.
Ea for F = -328
E11 forCs = +375.7
E12 for Cs = +2422
Heat of sublimation for Cs = 76.1
Bond dissociation energy for F2= +158
Lattice energy for CsF= +740 .
To calculate the overall energy change for the formation of CsF2 from its elements, we need to consider the individual energy changes involved in the process.
The formation of CsF2 from its elements involves the following steps:
1. Cs(s) --> Cs(g) (sublimation of cesium)
2. F2(g) --> 2F(g) (dissociation of fluorine)
3. Cs(g) + F(g) --> CsF(g) (formation of cesium fluoride)
4. CsF(g) --> CsF(s) (lattice formation of cesium fluoride)
Step 1: Cs(s) --> Cs(g)
The energy change for the sublimation of cesium is given as heat of sublimation for Cs = 76.1 kJ/mol.
Step 2: F2(g) --> 2F(g)
The energy change for the dissociation of fluorine is given as bond dissociation energy for F2 = +158 kJ/mol.
Step 3: Cs(g) + F(g) --> CsF(g)
The energy change for the formation of cesium fluoride gas is the sum of the ionization energy of cesium (E11 for Cs = +375.7 kJ/mol) and the electron affinity of fluorine (Ea for F = -328 kJ/mol).
Step 4: CsF(g) --> CsF(s)
The energy change for the formation of cesium fluoride lattice is the negative of the lattice energy for CsF = -740 kJ/mol.
To calculate the overall energy change for the formation of CsF2, we sum up the energy changes of each step:
Overall energy change = (Step 1) + (Step 2) + (Step 3) + (Step 4)
Overall energy change = (76.1 kJ/mol) + (158 kJ/mol) + (375.7 kJ/mol - 328 kJ/mol) + (-740 kJ/mol)
Overall energy change = 540.8 kJ/mol - 328 kJ/mol - 740 kJ/mol
Overall energy change = -527.2 kJ/mol
Therefore, the overall energy change for the formation of CsF2 from its elements is -527.2 kJ/mol.
To calculate the overall energy change for the formation of CsF2 from its elements, we need to consider the individual energy changes for each step involved.
1. First, we need to calculate the energy change for the formation of CsF from its elements Cs and F2:
Energy change = (Ea for F) + (E11 for Cs) + (Bond dissociation energy for F2) - (Lattice energy for CsF)
Energy change = (-328 kJ/mol) + (+375.7 kJ/mol) + (+158 kJ/mol) - (+740 kJ/mol)
2. Next, we need to account for the energy change for the sublimation of Cs:
Energy change = Energy change + (Heat of sublimation for Cs)
Energy change = Energy change + (+76.1 kJ/mol)
3. Finally, we can calculate the overall energy change for the formation of CsF2 from its elements (CsF + F):
Energy change = Energy change + Lattice energy for CsF2
Energy change = Energy change + (+2347 kJ/mol)
Adding all these energy changes together will give us the overall energy change for the formation of CsF2 from its elements.