The Rate of Dehydration of Copper Sulphate Pentahydrate at Low Pressures of Water Vapor

Abstract

The rate of dehydration of copper sulphate pentahydrate has been determined over a range of low pressures of water vapor. I t has beer1 found that a s the pressures are increased, the rate a t first drops very rapidly; this drop is followed by a period of marked acceleration, whicli is followed in turn by a gradual decline. Copper sulphate pentahydrate has bee11 found to be similar in this respect t o manganous oxalate dihydrate, which has been hitherto regarded as unique in its behavior. The observed effects are pro.bably due to amorphous to crystalline transitions occurring during induction periods, the durations of which have also been found to depend on water vapor pressure.

The Low Pressure Dehydration of Magnesium Sulphate Heptahydrate and Cobaltous Chloride Hexahydrate

“…I t would appear reasonable therefore to give the same interpretation of these curves as has been done for the copper sulphate pentahydrate dehydration (2). Under vacuum, the parent lattice breaks down into a state of monohydrate composition which does not yield a pattern of X-ray diffraction lines.…”

The Adsorption of Argon on Some Vacuum Dehydrated Salts

“…The rate of dehydration of inanganous oxalate dihydrate a t a series of low pressures of water vapor has been determined by Voliner and Seydel (11) and by Topley and Smith (10). Similar rate determinations for the dehydration of copper sulphate pentahydrate have been made by Frost and Campbell (4), who interpreted these rates in terms of the formation of an~orphous inaterial and its subsequent crystallization. Wheeler (12) and Ford (3) have studied the rates of dehydration of the other salts mentioned and found that all were qualitatively similar in the dependence of rate on the water vapor pressure in the vicinity of the reaction interface.…”

Calculation and optimization of the copper (II) sulphate monohydrate from copper (II) sulphate pentahydrate production process in a fluidized bed dryer

“…Mehanizam dehidratacije bakar(II)-sulfat-pentahidrata predmet je brojnih studija u proteklih osamdesetak godina [1][2][3][4]. Rezultati ukazuju da ovaj materijal ima neka jedinstvena termička svojstva.…”

“…Na oko 70 °C proizvod zagrevanja CuSO 4 •5H 2 O je trihidrat, CuSO 4 •3H 2 O. U ovom kristalohidratu, atomi kiseonika iz tri molekula vode i atom kiseonika iz sulfat-jona obrazuju deformisan kvadrat u kome su veze Cu(II) i atoma kiseonika iz molekula vode nešto kraće (0,196 nm). Daljim zagrevanjem, moguće je izvršiti potpunu dehidrataciju i dobiti anhidrovanu so, CuSO 4 , kod koje je Cu(II) vezan za atome kiseonika iz sulfat-jona [1][2][3][4].…”