# Liquids

If compounds are formed between two system components in the solid state, these compounds behave like pure substances and can crystallize out of the melt as separate phases (Laves phase). Intermetallic phases are particularly common and well investigated. The intermetallic Laves phase is formed in the magnesium / zinc system $\text{Mg}{\text{Zn}}_{2}$.

The phase diagram can be composed of the two partial diagrams $\text{Zn}$/$\text{Mg}{\text{Zn}}_{2}$and $\text{Mg}{\text{Zn}}_{2}$/$\text{Mg}$ think that qualitatively correspond to the SystemCd / Bi. The two parts show eutectics ((Fig. 1): A and B) with melting points of 380 and 347, respectively $° C$. The eutectic mixtures consist of finely crystalline mixtures of $\text{Mg}{\text{Zn}}_{2}$ and$\text{Zn}$ respectively $\text{Mg}{\text{Zn}}_{2}$ and $\text{Mg}$.

The mole fraction of 0.33 $\text{Mg}$ corresponds to the intermetallic phase $\text{Mg}{\text{Zn}}_{2}$, the dystectic ((Fig. 1): C).$\text{Mg}{\text{Zn}}_{2}$ melts at 590 $° C$.

Note
You can see that the basic substances $\text{Mg}$,$\text{Zn}$ and $\text{Mg}{\text{Zn}}_{2}$ the highest melting points.
Note
Form several compounds or intermetallic phases, for example ${\text{Cu}}_{2}\text{Mg}$and $\text{Cu}{\text{Mg}}_{2}$, the diagram also contains several maxima.
Example aniline / phenol

Analogous relationships can also occur with completely different classes of compounds. The basic aniline and the acidic phenol form the salt aniline phenolate, in which the two components are present in a ratio of 1: 1:

The phase diagram of the phenol / aniline system is similar to that of$\text{Mg}$/$\text{Zn}$.