Quantitative thermogravimetric analysis of binary mixtures: Magnesium hydroxide and magnesium acetate

Abstract

Thermogravimetric analysis is used to determine the amounts of Mg(OH) 2 and Mg(CH3COO)2 in a mixture thereof. The application and suitability of different analysis methods are discussed. In the first method the mass losses in the temperature ranges as indicated by the decomposition of the pure compounds were used. Results obtained using these temperature ranges were unusable. The percentage mass losses due to the decomposition of Mg(OH)2 and Mg(CH3COO)2 were then determined in a second method using the minimum in the derivative mass vs. temperature curves. The results obtained by this method compared well with the actual values for mixtures containing more than 15% magnesium acetate. The third method employed the total experimental mass loss of both decomposition reactions. The results obtained using this method compared well to the actual values, giving a R2 value of more than 0.99. This method of using the total mass losses can however only be used for binary mixtures that consist only of magnesium hydroxide and magnesium acetate.