來源:http://www.guangshe.com.cn/ 發(fā)布時間:2021-03-30
鋁的比熱容是0.88×103 J/(kg·℃), 溶點(diǎn):660.37鋁的熔解熱是3.98×105J/kg,鋁的蒸發(fā)熱是1.05× 107J/kg.熔解熱 單位質(zhì)量的晶體物質(zhì)在熔點(diǎn)時,從固態(tài)變成液態(tài)所吸收的熱量,叫做這種物質(zhì)的熔解熱。
The specific heat capacity of aluminum is 0.88 × 103 J / (kg ·℃), the melting point is 660.37, the melting heat of aluminum is 3.98 × 105 J / kg, and the evaporation heat of aluminum is 1.05 × 107 J / kg.
熔解熱: 單位質(zhì)量晶體物質(zhì),在熔點(diǎn)由固相轉(zhuǎn)變?yōu)橐合嗨盏南嘧儩摕帷>w的熔解是粒子由規(guī)則排列轉(zhuǎn)向不規(guī)則排列的過程。這些熱量就將用來反抗分子引力做功,增加分子的勢能,也就是說,這時物質(zhì)所吸收的熱量是破壞點(diǎn)陣結(jié)構(gòu)所需的能量,使分子的運(yùn)動狀態(tài)起質(zhì)的變化從固態(tài)的分子熱運(yùn)動轉(zhuǎn)變成液態(tài)的分子熱運(yùn)動,同時改變了物質(zhì)的狀態(tài)。
Melting heat: the latent heat of phase transformation absorbed by a unit mass of crystalline material when it changes from solid phase to liquid phase at the melting point. The melting of crystals is a process in which the particles change from regular arrangement to irregular arrangement. The heat will be used to resist the molecular gravity to do work and increase the potential energy of the molecule. In other words, the heat absorbed by the substance is the energy needed to destroy the lattice structure, which makes the motion state of the molecule change qualitatively from the solid molecular thermal motion to the liquid molecular thermal motion, and changes the state of the substance.
所以晶體不僅有固定的熔點(diǎn),而且還需要吸收一定數(shù)量的熱量來實(shí)現(xiàn)它的熔解。由于物質(zhì)不同其晶體空間點(diǎn)陣結(jié)構(gòu)不同,盡管各種不同物質(zhì)的質(zhì)量相同,但在熔解時所吸收的熱量卻不相同。
So the crystal not only has a fixed melting point, but also needs to absorb a certain amount of heat to achieve its melting. Due to different materials, the lattice structure of crystal space is different. Although the mass of different materials is the same, the heat absorbed during melting is different.
為表示晶體物質(zhì)的這一特性,而引入熔解熱。它表示單位質(zhì)量的某種固態(tài)物質(zhì)在熔點(diǎn)時完全熔解成同溫度的液態(tài)物質(zhì)所需要的熱量;該物質(zhì)在凝固時,在凝固點(diǎn),也等于單位質(zhì)量的同種液態(tài)物質(zhì),轉(zhuǎn)變?yōu)榫w所放出的熱量。
In order to express this characteristic of crystal material, the melting heat is introduced. It represents the heat required for a solid substance of unit mass to completely melt into a liquid substance at the same temperature at the melting point; when the substance solidifies, at the freezing point, it is also equal to the heat released by the same liquid substance of unit mass to transform into a crystal.
如果用λ表示物質(zhì)的熔解熱,m表示物質(zhì)的質(zhì)量,Q表示熔解時所需要吸收的熱量,則 Q=λm 熔解熱的單位是焦耳/克或焦耳/千克。測量熔點(diǎn)較高的物體的熔解熱是比較困難的,但是對于熔點(diǎn)較低的物體,就可以用量熱器來測定。
If λ is used to denote the melting heat of a substance, M is the mass of the substance, and Q is the heat to be absorbed during melting, then q = λ m, the unit of melting heat is Joule / g or Joule / kg. It is difficult to measure the melting heat of the object with high melting point, but for the object with low melting point, it can be measured by calorimeter.