DonnieBrasco
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In terms of determining the size (large being most exothermic) of the lattice enthalpy, are the factors affecting it for:

Theoretical: Large values generated by a small ionic radius for both the cation and anion (meaning they can get closer in the lattice) and large magnitudes for the charges of the cation and anion

Experimental: Small highly charged (polarising) cations and large (polarisable) anions, meaning that there is covalent character in the bond.

Is this correct?

Also out of K2O, LiI, LiF and CaO will it be LiI that shows the most deviation from the theoretical value calculated from the Born-Lande equation and the experimental value? My reasoning is that Li+ is small and will have a fairly large charge density, and although it doesn't have as large a charge compared to Ca2+ the anion I- is more polarisable than O2-. Meaning that there will be significant covalent character (which the B.L. equation doesn't take into account).

Thanks
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username913907
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(Original post by DonnieBrasco)
In terms of determining the size (large being most exothermic) of the lattice enthalpy, are the factors affecting it for:

Theoretical: Large values generated by a small ionic radius for both the cation and anion (meaning they can get closer in the lattice) and large magnitudes for the charges of the cation and anion

Experimental: Small highly charged (polarising) cations and large (polarisable) anions, meaning that there is covalent character in the bond.

Is this correct?

Also out of K2O, LiI, LiF and CaO will it be LiI that shows the most deviation from the theoretical value calculated from the Born-Lande equation and the experimental value? My reasoning is that Li+ is small and will have a fairly large charge density, and although it doesn't have as large a charge compared to Ca2+ the anion I- is more polarisable than O2-. Meaning that there will be significant covalent character (which the B.L. equation doesn't take into account).

Thanks
All sounds good to me Just don't make the mistake of thinking that Li+ is a small cation, many people do.
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DonnieBrasco
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Brilliant, thanks
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