A laboratory technician needs to prepare a pure, dry sample of hydrated nickel(II) sulfate crystals, NiSO4⋅7H2O\text{NiSO}_4 \cdot 7\text{H}_2\text{O}NiSO4⋅7H2O. The starting materials available include nickel(II) carbonate (NiCO3\text{NiCO}_3NiCO3) and a selection of dilute mineral acids.
Plan a detailed laboratory method to prepare pure, dry crystals of nickel(II) sulfate using nickel(II) carbonate and a suitable dilute acid.
Identify two other nickel-containing substances that could each be reacted with a suitable dilute acid to yield nickel(II) sulfate.
Do not refer to nickel(II) carbonate in your response.