Chemical reaction: MnSO₄·7H₂O → MnSO₄·H₂O + 6H₂O. MnSO₄·7H₂O is <span>manganese(II) sulfate heptahydrate. </span>MnSO₄·H₂O is <span>manganese(II) sulfate monohydrate. Manganese has oxidation number +2 and sulfate anion has oxidation number -2. For </span><span>crystallization water h</span>epta means seven and mono means one.