# 热物理学和物质属性 Thermal Physics and Properties of Matter  PHYS102

$$\Delta_{\text {vit }} H=\Delta_{\text {fus }} H\left(T_{\mathrm{g}}\right)=\Delta_{\text {fus }} H\left(T_{\mathrm{m}}\right)+\frac{3}{2} \frac{\Delta_{\text {fus }} H\left(T_{\mathrm{m}}\right)}{T_{\mathrm{m}}}\left(\frac{2}{3} T_{\mathrm{m} \mathrm{}}-T_{\mathrm{m}}\right)$$
or
$$\Delta_{\text {vit }} H=\frac{1}{2} \Delta_{\text {fus }} H\left(T_{\mathrm{m}}\right)$$

## PHYS102 COURSE NOTES ：

$$R_{i} \leq \frac{x+y+2(1-x-y)}{1-x-y}=\frac{2-x-y}{1-x-y} \leq R_{i+1}$$
Then the mole fractions, $x\left(\mathrm{Q}^{i}\right)$, of particular $\mathrm{Q}$-units are calculated from the mass balance equations:
$$(1-x-y)\left[x\left(\mathrm{Q}^{i}\right)(i / 2+4-i)+x\left(\mathrm{Q}^{i+1}\right)(i / 2+7 / 2-i)\right]=2-x-y$$
$$x\left(Q^{i}\right)+x\left(Q^{i+1}\right)=1$$
Unfortunately, the above approach can be used for the rough orientation purposes only. In fact, Q-units disproportionate and the Q-distribution is given by the equilibrium of the disproportionation reactions of the type:
$$2 \mathrm{Q}^{n} \leftrightarrow \mathrm{Q}^{n+1}+\mathrm{Q}^{n-1}, \quad n=1,2,3$$