How to make a Desiccator Bag for Drying Chemicals

In this video we make a desiccator bag for thoroughly drying hygroscopic chemicals. Some chemicals are hygroscopic, meaning they absorb water from the air and become moist, mushy, or even liquefy. For highly accurate work and good results in experiments the chemicals should be dried before use. A laboratory device for doing this is called a desiccator.

Laboratory desiccators use vacuum and drying agents. A simple home desiccator can be made from an airtight resealable plastic bag and a hygroscopic drying agent like sodium hydroxide.

Simply get a plastic container and fill it up with sodium hydroxide, then place it inside the bag along with a container of the chemical you intend to dry. Seal it up and wait.

Thorough drying can take weeks. Sometimes you might run into the problem where the top dries before the bottom, you'll have to grind your chemical every so often to continue drying.

The bag is also good for storing already dry chemicals to keep them dry. After using a chemical, return the unused portion to the bag to dry out the tiny bit of humidity it absorbed while you were working it.

Other drying agents you can use are:
Potassium hydroxide
calcium chloride
silica gel
sodium sulfate
magnesium sulfate
calcium sulfate
molecular sieves
sulfuric acid

I don't use glass because the agents might dissolve glass. Plastic container are cheap and disposable.

This desiccator only works on solids, it does not work on liquids and cannot be used for concentrating acids, peroxide or drying alcohols.

Category:

Science & Technology

Tags:

• Desiccator
• vacuum
• science
• chemistry
• nurd
• rage
• experiments
• laboratory
• equipment

[pyrogirl1985]

Ive made this bag and my bag begins to decompose, just like the way your soft drink decomposes. I am using sodium hydroxide I have also used silica gels and the same effect occurs what have I done wrong?

[NurdRage]

bag might be made of an ester-based polymer which is susceptible to hydroxide. i reccomend putting the sodium hydroxide in a tin can or finding a bag from a different brand. Not all bags are susceptible to hydroxide.

[TheCrazyFinn]

Would it be possible to utilize this, while conducting a synthesis, using HNO3, which produces a byproduct of H2O?

[burnzzzification]

so using this to dry my weed

[TheChemicalGenius]

@NurdRage Do you know of a dessicant that won't react with HCl gas?

[ScienceTry]

@gehtomacgyver To make it solid is really difficult.... but if you want you can heat the

hydroxide until it dries.

[tomytherose]

i wanna dry 200 ml of hydrogen peroxid 3 % so will i get after a few days 20 ml of 30 % hydrogen peroxid?

[Ztuibyman]

Hey, I have a question: could I use vacuuming method instead of a deccicator bag because I think, if a liquid is in extreme vacuum, it would be forced to evaporate, leaving the crystals behind?

[kitty6837]

@JakeXVX Try re-crystallization.

[flamingchucknorris]

im trying to make rust oxide by connecting an iron rod to a positive terminal and putting it in water with the negative terminal in the water. I am making this for later production of thermite, but its taking FOREVER to dry, and when i tried cooking it, i barely got any rust oxide. I think its hygroscopic, but i dont want to waste time making a desiccator bag i dont need.

[OOZ662]

@rzezagar I don't see why not. It's just the transfer of moisture from one substance to another. It's like placing ice in water with something to transfer the cold from the ice to the object, except you're moving moisture through air instead.

[Magicjeffff]

... and if it starts eating through it's contaier, it DEEEEEFINAELY needs to be replaced. lmao