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## Experiment No. 8 **Aim:** To prepare a pure sample of ferrous ammonium sulphate. **Theory:** * Mohr's salt is one of the important laboratory reagents and used as a reducing agent. * Chemically Mohr's salt is ferrous ammonium sulphate (FAS). * It is prepared by dissolving an equimolar mixtur...

## Experiment No. 8 **Aim:** To prepare a pure sample of ferrous ammonium sulphate. **Theory:** * Mohr's salt is one of the important laboratory reagents and used as a reducing agent. * Chemically Mohr's salt is ferrous ammonium sulphate (FAS). * It is prepared by dissolving an equimolar mixture of hydrated ferrous sulphate (FeSO4.7H2O) and ammonium sulphate [(NH4)2SO4] in acidified water. * Mohr's salt [FeSO4. (NH4)2SO4 · 6H2O] crystallizes as pale green colored solid. **Chemical Equation:** $FeSO_4.7H_2O + (NH_4)_2SO_4 \longrightarrow FeSO_4. (NH_4)_2SO_4. 6H_2O + H_2O$ **(278)** **(132)** **(392)** **Apparatus:** china dish, beakers, funnel, glass rod, tripod stand, wire gauze, pair of tongs etc. **Chemicals:** Ammonium sulphate, ferrous sulphate, dilute sulphuric acid etc. **Procedure:** 1. Weigh accurately 3.5g ferrous sulphate and 1.5g ammonium sulphate and transfer into 100 mL beaker. Add about 2-3mL