MediumChemistryHigh School (11–12)Chemical Bonding › Lewis Structures and Ionic BondsNumericalBoard ExamA-LevelIB
For potassium chloride, in kJ/mol: sublimation of potassium +89, half the bond enthalpy of chlorine…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
For potassium chloride, in kJ/mol: sublimation of potassium , half the bond enthalpy of chlorine , ionisation of potassium , electron gain of chlorine , and enthalpy of formation of KCl . Find the lattice enthalpy.
Need a reminder? The key ideaShow
Born-Haber cycle: enthalpy of formation sublimation half the bond enthalpy ionisation enthalpy electron gain enthalpy lattice enthalpy. The lattice enthalpy is the energy needed to separate one mole of an ionic solid into its gaseous ions. It grows with the charges of the ions and as the ions get smaller.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. The cycle. .
Step 2. Add the known steps. .
Step 3. Solve. kJ/mol.
Answer: kJ/mol.
Discussion (0)
Log in to join the discussion.
Loading…