Nickel(II) sulfate, or just nickel sulfate, usually refers to the inorganic compound with the formula NiSO4(H2O)6. This highly soluble blue-coloured salt is a common source of the Ni2+ ion for electroplating. Nickel sulfate is paramagnetic.

Nickel nitrate is the chemical compound Ni(NO3)2 or any hydrate thereof.
Nickel Nitrate is Fire-hazardous oxidant; deliquescent, green crystals; Soluble in water, alcohol and ammonia solution

Nickel(II) acetate (Ni(CH3COO)2)is an inorganic compound of nickel and acetic acid. This inorganic compound is usually found as the tetrahydrate. It is used for electroplating.

Nickel(II) carbonate describes one or a mixture of inorganic compounds containing nickel and carbonate. From the industrial perspective, the most important nickel carbonate is basic nickel carbonate with the formula Ni4CO3(OH)6(H2O)4. Nickel carbonates are used in some ceramic applications and as precursors to catalysts.