Mohr’s salt is a ferrous ammonium salt also called double salt represented by [FeSO4(NH4)2SO4.6H2O]. It is prepared by dissolving equimolar quantities of ferrous sulphate and ammonium sulphate in hot water containing little H2SO4. This solution on cooling gives green blue crystal called Mohr’s salt.
- It is pale green crystalline compound.
- It is non-efflorescent and chemically similar to ferrous sulphate.
- It is a strong reducing agent. It reduces KMnO4, K2Cr2O7 etc.
- It is used as a laboratory reagent.
- It is used to kill the moss without harming the grass.