Double salts should not be confused with
complexes. Double salts only exist in the solid. When dissolved in water, a double salt acts as a mixture of the two separate salts: it completely dissociates into simple ions while a hexaaquo complex does not; the
complex ion remains unchanged. Similarly, potassium hexaiodoytterbate(II) K4[YbI6 is a complex salt and contains the discrete hexaiodoytterbate(II) ion [YbI64−, which remains intact in
aqueous solutions.[1] In many cases, the
complex ion is indicated by square brackets "[ ]". Double salts are distinct from mixed-crystal systems where two salts
cocrystallise;[2] the former involves a chemical combination with fixed composition, whereas the latter is a mixture.[3]
In general, the properties of the double salt formed will not be the same as the properties of its component single salts.
Double salts should not be confused with
complexes. Double salts only exist in the solid. When dissolved in water, a double salt acts as a mixture of the two separate salts: it completely dissociates into simple ions while a hexaaquo complex does not; the
complex ion remains unchanged. Similarly, potassium hexaiodoytterbate(II) K4[YbI6 is a complex salt and contains the discrete hexaiodoytterbate(II) ion [YbI64−, which remains intact in
aqueous solutions.[1] In many cases, the
complex ion is indicated by square brackets "[ ]". Double salts are distinct from mixed-crystal systems where two salts
cocrystallise;[2] the former involves a chemical combination with fixed composition, whereas the latter is a mixture.[3]
In general, the properties of the double salt formed will not be the same as the properties of its component single salts.