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铜、镍,钴铍氟酸盐水合物晶体与相应的硫酸盐水合物晶体属同晶结构。原因在于BeF_4~=与SO_4~=具有相同的电子数目及外层电子数目。但是BeF_4~=与SO_4~=中心原子的氧化值不同,极化能力不同,故Be-F键应比S-0键为弱,热稳定性应较低。通过差热及热重量分析配合化学分析及X射线粉末法对热分解产物的鉴定,说明在400℃以下硫酸盐水合物只是简单可逆脱水,可表示为: CuSO_4·5H_2O 80℃ CuSO_4·4H_2O+H_2O 104℃ CuSO_4·3H_2O+2H_2O 123℃ CuSO_4·H_2O+4H_2O 228℃ CuSO_4+5H_2O NiSO_4·6H_2O 105℃ NiSO_4·3H_2O+3H_2O 125℃ NiSO_4·H_2O+5H_2O 346℃ NiSO_4+6H_2O CoSO_4·6H_2O 96℃ CoSO_4·H_2O+5H_2O 300°-330℃ CoSO_4+6H_2O 铍氟酸盐水合物脱水是不可逆的,第一步: CuBeF_4·5H_2O 102℃ CuBeF_4·4H_2O+H_2O NiBeF_4·6H_2O 105℃ NiBeF_4·4H_2O+2H_2O CoBeF_4·6H_2O 110℃ CoBeF_4·4H_20+2H_2O 脱水后样品溶于结晶水中,当溶液沸腾时BeF_4~=发生水解,生成Be(OH)_2、BeF_2及CuF_2·2H_2O或NiF_2·2H_2O或CoF_2·2H_2O放出HF。温度稍高CuF_2·2H_2O、 NiF_2·2H_2O,CoF_22H_2O又分解成CuOHF·CuF_2、NiF_2及CoF_2。在220℃附近Be(OH)_2脱水成BeO。在350℃以上CuF_2还会变成CuO。
The copper, nickel, cobalt beryllium hydrofluoride hydrate crystals are isomorphic to the corresponding sulfate hydrate crystals. The reason is that BeF_4 ~ = has the same number of electrons and outer electrons as SO_4 ~ =. But BeF_4 ~ = and SO_4 ~ = oxidation of the central atom of different values, polarization ability is different, so the Be-F bond than the S-0 bond is weak, the thermal stability should be low. Differential thermal and thermogravimetric analysis coupled with chemical analysis and X-ray powder analysis of the thermal decomposition products, indicating that the sulfate hydrate below 400 ℃ is only a simple reversible dehydration can be expressed as: CuSO_4 · 5H_2O 80 ℃ CuSO_4 · 4H_2O + H_2O 104 ℃ CuSO_4 · 3H_2O + 2H_2O 123 ℃ CuSO_4 · H_2O + 4H_2O 228 ℃ CuSO_4 + 5H_2O NiSO_4 · 6H_2O 105 ℃ NiSO_4 · 3H_2O + 3H_2O 125 ℃ NiSO_4 · H_2O + 5H_2O 346 ℃ NiSO_4 + 6H_2O CoSO_4 · 6H_2O 96 ℃ CoSO_4 · H_2O + 5H 2 O 300 ° -330 ° C CoSO 4 + 6H 2 O beryllium fluoride hydrate dehydration is irreversible, the first step: CuBeF_4 · 5H_2O 102 ℃ CuBeF_4 · 4H_2O + H_2O NiBeF_4 · 6H_2O 105 ℃ NiBeF_4 · 4H_2O + 2H_2O CoBeF_4 · 6H_2O 110 ℃ CoBeF_4 · 4H_20 + 2H_2O dehydrated sample is dissolved in crystal water. BeF_4 ~ = is hydrolyzed to form Be (OH) _2, BeF_2 and CuF_2 · 2H_2O or NiF_2 · 2H_2O or CoF_2 · 2H_2O when the solution boils. The slightly higher temperature CuF_2 · 2H_2O, NiF_2 · 2H_2O, CoF_22H_2O decomposed into CuOHF · CuF_2, NiF_2 and CoF_2. Dehydration of Be (OH) 2 to BeO at 220 ℃. CuF 2 will also become CuO above 350 ° C.