Preparation and Heat of Formation of a Magnesium Oxysulfate
Abstract:
Magnesium oxysulfate, 3Mg(OH)2·MgSO4·8H2O, was precipitated from metastable aqueous solutions of MgO in MgSO4. The compound forms in solutions containing 12 percent or more of MgSO4, and remains unchanged in solutions containing 10 percent MgSO4, but at lower concentrations is converted to Mg(OH)2. Magnesium hydroxide is not converted to the oxysulfate by nearly saturated MgSO4 solutions in times up to three years. The solubility of the oxysulfate is given in the form of a plot of the basicity and MgSO4 content of magnesium sulfate solutions. The heat of solution of the oxysulfate compound in HCl·26.61H2O (2.000 normal at 25 °C) is 68.94 kcal/mole with a standard deviation of 0.23 kcal/mole and its heat of formation from Mg(OH)2, MgSO4·7H2O, and liquid water is ΔH=2.11 kcal/mole. The corresponding heat of formation from the elements is -1537.9 kcal/mole.
Related Concept Videos
Preparation and Reactions of Sulfides
Washing, Drying, and Ignition of Precipitates
Qualitative Analysis
For instance, group IV...
Weak Acid Solutions
Preparation of Epoxides
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...
Preparation of Carboxylic Acids: Carboxylation of Grignard Reagents


