[chbE44]

Hello!

      I left nickel nitrate out of our dessicator for a few months. If I put it back in will it return to the hexahydrate complex? I also have the same question with regard to lanthanum nitrate.

Thanks in advance

[Arkcon]

I really can't be sure.  It may have absorbed moisture out of the desiccator, so its mass will be wrong when you try to use it for preparing an analytical solution.  You may be able to return it to new condition, if you can find a procedure online, but it may not be worth your time.  If you have access to a Karl-Fisher apparatus, you might be able to quantify the moisture, and see if it still meets specification.