Sciencemadness Discussion Board

A wee little drying experiment.

PirateDocBrown - 6-1-2018 at 07:57

Scored a glass desiccator from University Surplus for $20.

Filled its bottom with store-bought DampRid.

I had made some dessicated MgSO4 by heating Epsom salt in the oven, and put some of this into a porcelain casserole. I stained it with a bit of CoCl2 solution I made up from CoCl2 I got from Elemental Scientific. The solution, of course was pink, the color of the hydrated Co (II) ion, and it stayed pink when added to the MgSO4.

However, after a few days in the dessicator, exposed to the CaCl2 DampRid, it turned blue! (The proper color of anhydrous Co (II) ions).

Apparently, DampRid has the power to pull moisture off of wet MgSO4. Good info.

Also good: I now have the capacity to make my own indicating drying agents.

Next to tinker with other substance combos.

NEMO-Chemistry - 6-1-2018 at 14:54

try sodium chloride (oven dried) with 20% dry basmati rice well mixed in as the desiccator. So far its dried most things out and is dead cheap.

CaCl2 - 6-1-2018 at 15:35

Wow, a desiccator for only 20$.

For some reason they tend to be pretty expensive, I haven't even been able to find any made from glass much less than 50$ (including shipping), there seem to be no Chinese eBay sellers selling cheap ones, unlike with most other equipment.

I have no idea why, luckily any kind of airtight jar seems to work OK as a replacement.

I have used calcium chloride and oxide as desiccants, both have worked as expected.
The chloride is weaker, but unlike the oxide it be recycled by heating.



[Edited on 7-1-2018 by CaCl2]

PirateDocBrown - 6-1-2018 at 17:41

It was used, and chipped up, and the lid was mismatched, bur it's perfectly functional, with a bit of silicone grease.

zed - 7-1-2018 at 12:58

Yup. Never see 'em cheap. Just a big piece of glass, as far as I know.

NEMO-Chemistry - 7-1-2018 at 17:19

Quote: Originally posted by zed  
Yup. Never see 'em cheap. Just a big piece of glass, as far as I know.

I think its because the top and bottom are matched. Dont mix the tops up on vac ones