Product Overview

Ferrous Ammonium Sulphate Hexahydrate 99% AR/ACS (CAS No. 7783-85-9) is Mohr’s salt, a crystalline iron(II)–ammonium double sulphate used as a stable source of ferrous ions in quantitative redox chemistry. Its defined hexahydrate composition permits accurate reagent-solution preparation, while the sulphate medium helps maintain iron in the divalent state more effectively than many simpler ferrous salts during ordinary laboratory handling.

The AR/ACS grade is intended for preparation and standardisation of ferrous titrant solutions, oxidation–reduction analysis and analytical method verification. It is widely used as a reducing titrant in dichromate-based chemical oxygen demand procedures and in reactions involving permanganate, dichromate, cerium(IV) or other method-specified oxidants. Careful acidification and protection from atmospheric oxidation support reproducible analytical response.

Typical Applications

• Preparation and standardisation of ferrous ammonium sulphate titrants
• Back-titration of dichromate in chemical oxygen demand analysis
• Standardisation of oxidising reagent solutions
• Redox titrations involving permanganate or dichromate
• Cerimetric and related oxidation–reduction procedures
• Preparation of non-certified iron(II) working solutions
• Verification of ferroin-indicated redox endpoints

Common Synonyms

• Mohr’s salt
• Ammonium iron(II) sulphate hexahydrate
• Ammonium ferrous sulphate hexahydrate
• Ferrous ammonium sulfate hexahydrate
• Ammonium iron(II) sulfate hexahydrate

Storage Conditions

Keep tightly sealed and protect from air, moisture, excessive heat and analytical contamination. Prepared ferrous solutions should be suitably acidified where prescribed by the method, protected from prolonged air exposure and restandardised when required.