Cerium rare earth compounds occur as either III or IV valences, and most of cerium is used in glass polishing, among other uses. China is by far the biggest producer, and cerium is the most abundant of the rare earth metals. Cerium IV sulfate is primarily used in analytical laboratories for inorganic testing/analysis.
Ceric sulfate 0.1N is used in redox titration analysis. It is most stable in a 1-2 normal sulfuric acid matrix. It is preferred over potassium permanganate for iron titrations. Reagent grade ceric sulfate should have very low specifications for iron, phosphate and calcium. It can also be used to determine hydrogen peroxide, oxalates, and arsenite.
Ceric sulfate can also be prepared from cerium hydroxide with concentrated sulfuric acid, but this is time consuming and requires special safety gear. The yield is also considerably less than 100%, with some unreacted oxide typically left over. Ceric sulfate is also available in hydrated forms.
One advantage of ceric sulfate normality solutions is that the yellow color itself serves as the indicator, so no additional indicator is required. When assaying or standardizing ceric sulfate, the preferred choices for standards are oxalic acid or sodium oxalate. Another advantage is that cerium is a relatively low hazard element and is safe to handle during titrations.
Exaxol offers a variety of standardized ceric sulfate solutions, all of which are standardized within 0.2% accuracy of stated value and conform to ISO 17025 and ISO 9001 requirements . These are typically in stock and ready to ship promptly.