1. Hydration energy is the energy released when 1 mol of a
substance is dissolved into a solution.
It is always negative, as bonds (e.g. dative, ion-dipole) are being
formed. When the solvent is other than water the process is
referred to as solvation..
The enthalpy change of a solution is equal to the sum of three
different energy transfer processes
first is the lattice energy, the second is enthalpy change of
hydration of cation and the third is the
enthalpy change of hydration of anion. By definition, the enthalpy
change of hydration Delta H hyd is the enthalpy change that takes
place when 1 mole of gaseous ion is dissolved in excess water to
make one mole aqueous ion. The relationship depends on the charge
density of the ions being hydrated - Higher charge density, more
exothermic reaction and higher hidration energy.
So the answer is c) K+ because it has least charge density.
1. Hydration energy is the energy released when 1 mol of a substance is dissolved into a solution.
It is always negative, as bonds (e.g. dative, ion-dipole) are being formed. When the solvent is other than water the process is referred to as solvation..
The enthalpy change of a solution is equal to the sum of three different energy transfer processes
first is the lattice energy, the second is enthalpy change of hydration of cation and the third is the
enthalpy change of hydration of anion. By definition, the enthalpy change of hydration Delta H hyd is the enthalpy change that takes place when 1 mole of gaseous ion is dissolved in excess water to make one mole aqueous ion. The relationship depends on the charge density of the ions being hydrated - Higher charge density, more exothermic reaction and higher hidration energy.
So the answer is c) K+ because it has least charge density.
12 pts) 21. Which ion-dipole interaction below results in the smallest (less negative) hydration energy? water...