Consider the following information. the lattice energy of cscl is δ h lattice = − 657 kj/mol. the enthalpy of sublimation of cs is δ h sub = 76.5 kj/mol. the first ionization energy of cs is ie 1 = 376 kj/mol. the electron affinity of cl is δ h ea = − 349 kj/mol. the bond energy of cl 2 is be = 243 kj/mol. determine the enthalpy of formation, δ h f , for cscl ( s ) .

-310.5 kJ/mol

Explanation:

The CsCl(s) will be formed by steps:

The metal (Cs) will be made gaseous by a sublimation → ΔHsub = 76.5 kJ/mol;The metal gains energy to ionize → IE = 376 kJ/mol;The nonmetal (Cl) loses energy to ionizes → EA = -349 kJ/mol;The nonmetal is bonded → BE = 243 kJ/mol;The lattice is formed → ΔHlattice = -657 kJ/mol.

The enthanlpy of formation is the sum of all the energies involved in the steps:

ΔHf = 76.5 + 376 -349 + 243 -657

ΔHf = -310.5 kJ/mol

8a=38+8a²

Step-by-step explanation:

8a-3=5(a+7)+3a

8a-3=5a+35+3a

8a-3=8a²+35

8a=35+3+8a² (I moved 3 to put it with 35 because they are the same, I couldn't do the same for 8a and 8a² because of the 2)

8a=38+8a²

HOPE IT WORK