Step 1: 1/2 bond dissociation energy of Cl2(g) -Known (122 kJ/mol) Step 2: Enthalpy of sublimation of Na(s) - Known (107.3 kJ/mol) Step 3: Ionization energy of Na(g) - Known (496 kJ/mol) Step 4: Electron affinity of Cl(g) - Known (-349 kJ/mol) Step 5: Lattice formation energy of NaCl - Unkown Step 6: Enthalpy of formation of NaCl - Known (-411 kJ/mol)
this is specific to transition of NaCl but keep the steps in mind
That is, the energy difference between two states is independent of the energy used to transition between the states.
if the temperature and pressure is the same for two different moles of the same gas, the energy change from the phase transition is the same for both moles even if they were forced to change phases by different means
endothermic (breaking the bonds), and the other is exothermic (making the bonds).
higher stability=lower energy
energy change when a mole of an ionic compound is dissociated into its gaseous ions (an endothermic process with a positive value).
wouldn't dissociating an ionic compound result in the loss of some potential energy due to ions of like charges being farther apart therefore minimizing the repulsion between them? I know ultimately, transitioning to a gaseous phase is endothermic because the molecules gain kinetic energy, but is the loss of potential energy considered in the born haber cycle?
The first is that the smaller the ion, the greater the lattice energy.
is this because the smaller the ions, the closer an ion is to another ion of a like charge? or because periodic trends associated with smaller atoms?
form a lattice that minimizes repulsion between like charges while maximizing the attraction between opposite charges. Second, the anion and cation are different entities, and may have completely different volumes.
Enthalpy of hydration is negative because adding H2O within the lattice neutralizes the repulsion between ions with like charges. Neutralizing the repulsion decreases the potential energy withing the lattice and therefore results in a negative enthalpy.
Believe it or not, metals form simple crystal structures that we may not see on the macroscopic level.
I previously believed that metallic bonds from solids that had a "sea of electrons" that flowed amongst fixed nuclei. Confused as to how they for crystal structures.