Magnesium hydroxide is an inorganic substance with the chemical formula Mg(OH)2, white amorphous powder or colorless hexagonal column crystals, soluble in dilute acid and ammonium salt solution, almost insoluble in water, the part dissolved in water is completely ionized, and the aqueous solution is weakly alkaline.
In the composition of magnesium hydroxide, some customers require the determination of magnesium oxide content, magnesium oxide determination method is: with a small amount of triethanolamine masking trivalent iron, trivalent aluminum and plasma two manganese valence, at pH value of 10, with chromium black T as an indicator, the weight of the two standard titration solution with EDTA disodium titration method to determine the calcium and magnesium, calcium is subtracted from the content, calculate the magnesium oxide content. However, the accuracy of the results is often constrained by many factors, sometimes with large errors.
1, master the ambient temperature in different seasons. The test environment temperature has a great impact on the test data, especially the difference in winter, to strictly control the room temperature, so as not to affect the solution concentration, titration reaction speed.
2, the determination of the titration endpoint is accurate. The speed of the titration near the titration endpoint must be slow, carefully observe the changes in the color of the indicator to ensure that the endpoint of the titration is accurate.
3, Timing calibration of standard solution concentration. Strictly calibrate the concentration of EDTA standard solution with zinc oxide reference to reduce the error. The concentration of the concentration of the solution is 4, the standard solution preparation EDTA should meet the standard as far as possible.