Sealed tube differential thermal analysis studies of some nickel(II) salt hydrates

Sealed and open tube DTA curves are reported for nickel sulfate, nitrate, ammonium sulfate, chloride, acetate, formate and perchlorate hydrates. The endothermic peaks for the sealed tube reactions were smaller than those found for the open tubes, due to the lack of water vaporization in the former. With the exception of NiSO₄-(NH₄)₂SO₄-6H₂O, the peaks for the sealed and open tube reactions appeared at about the same initial peak temperature. The sealed tube reaction intervals (T_f-T_i) were shorter than those found for the open tube.