THE COORDINATION IN CRYSTALS

Finally, the ions Na+ and PtCl have to be combined to form the solid, so that the energy of complex formation will be 

Decomposition Temperatures of the Carbonates of Alkaline-Earth Metals 

The carbonates of the elements of the third group of the periodic system are less stable still. AI2(C03)3 apparently decomposes at 

On the other hand, sulphates of tervalent metals dissociate easily. The old process for the preparation of H2S04 was based on the dissociation of ferric sulphate, the SOs being absorbed in moderately dilute sulphuric acid. In this manner fuming sulphuric, or Nord-hausen, acid can be prepared. 

Aluminium sulphate decomposes on heating into A1203 and S03, while the rare-earth sulphates are much more stable. Tetravalent sulphates of the type Z(S04)2 occur very rarely, and of the metals of the fourth column, only thorium, because of its large ionic radius, forms a sulphate of this type. 

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