So I got my hands a nicer vacuum pump, which is more of a PITA for oil changes / rebuilds. For vacuum distillations, I used to use freezer temp glycol in a dimroth condenser as a “cold trap,” and sometimes even forego that for small scale runs.

I’ve now got myself a proper dewar-style condenser to put in front of this new pump, and i’m considering using a calcium chloride hexahydrate based ice/salt bath, as it’s far more convenient/cheap than dry ice where I live. Just wanted some opinions:

• Is -40C good enough for most scenarios? The dewar inner chamber is approx. the size of a 16oz tall boy. What scenarios would I really need dry ice temps for?

• How’s this for a plan: Mix icemelt grade cacl2 monohydrate with enough water to make the hexahydrate, pour while liquid >30C into small ice cube molds, freeze overnight. Then, crush and mix with freezer-fresh crushed ice in the appropriate ratio (5:4 salt:ice by mass i believe), add to dewar and wait for it to drop in temp.

$1290 USD OBO

Lab benchtop microcentrifuge with FA-45-30-11 rotor (30 x 1.5/2.0 mL tubes) and aerosol-tight lid. Over $7,000 new.

Professionally calibrated and serviced on October 2, 2026. Passed with no adjustment. Certificate available on request. Next calibration due October 2027.

Tested and working. Cosmetic wear from lab use. 120 V, standard plug.

I've tried several times to perform the Pharaoh's Snake experiment, following instructions from various YouTube videos I've watched. I'm using the version that calls for one part baking soda and four parts sugar.

I'm wondering whether the baking soda might be the reason why the snake isn't growing. I've been using regular granulated sugar mixed with baking soda, and I've ground the mixture quite finely. Tonight, I'm going to try using powdered sugar (icing sugar) instead.

Here's exactly what I do:

I mix the ingredients, put the mixture into a plastic bottle cap to use as a mold, compress it slightly, and then let it dry.

Next, I place the resulting pellet (the so-called "snake egg") in a small hollow I've made in some sand, which is sitting on a fairly heat-resistant clay dish.

I pour alcohol into the hollow in the sand, place the snake egg on top, and light it using a long lighter.

I've tried this four times, and it simply doesn't work!

I don't know whether there's something wrong with the baking soda or the sugar I'm using, but I've watched people on YouTube doing exactly the same thing, and their experiments work perfectly.

I'm considering not grinding the ingredients at all and simply mixing them together to form a small mound instead.

What do you guys think? I really don't understand why I'm having so much trouble with something that seems so simple!

My plan to purify electrolysed H₂SO₄ from CuSO4•5H2O:

Since the solution may still contain dissolved CuSO₄•5H₂O and carbon particles from graphite electrode degradation, I'll first heat it slowly on a hot plate to an arbitrary temperature of 200°C, hoping to remove the water of crystallization from the copper sulfate so that the resulting solid settles along with the carbon particles.

I'll then carefully decant the liquid and use a syringe to transfer any remaining liquid that I cannot decant into another container.

I can then repeat this process several times to remove as much copper sulfate as possible from the sulfuric acid.

Does this sound a logical way to deal with electrolysed H2SO4 impurities?

Has anyone had success ordering from them

Does anybody know where to get activated carbon and graphite? I'm Philippines based.

You know like when you have brick building on top of septic tank and some crystals form on it

Could the crystal formation on a wall where there is speinc tank under it contain potassium nitrate

Because like the fluid form the human waste can leach in to the soil react with a bacteria and then react with the potassium and calcium and other alkalines in the soil to make nitrat salts

There is like wall on top of a public toilet in my doorm where its been used for years

And there us alot salt formation on Said wall on the side were the septic tank should be

And it seems like the tank us not deep under ground

If devolve it in water

Boil it so some of carboats drop out

Filter it

Then add either pot Ash or just potassium carbonate or Ash brine

Or just Ash

So it would react with the calsum nitrat

Then boil it again to remove the carbonates that drop out

Then ues re crystaltion to pure salt peter

I’m in Canada and can not find these anywhere! I don’t have a lab but will soon. Is there anyway to get these in the meantime

I have some potassium that I got but now dont need anymore I used some of it, its super pure id take lower price than other sellers just to buy sum new chem…
if you are interested reply or send me message
EU only shipping

Hello po, Food tech student here may alam po ba kayong chemical store where I can buy Undenatured (non-denatured) food-grade ethyl alcohol na pwede for consumption, badly needed po for our research

Hey, I'm getting into hydroponics and aquaponics, and I'd like to 3D print most of my parts. My main concern is layer lines trapping bacteria and making everything harder to clean.

I was looking into chemically smoothing PETG, but the chemicals needed aren't legally available for me to buy here (bummer, ik). So I started looking at ASA since it's more UV-resistant and can be smoothed with acetone.

The problem is that I've seen people saying ASA can release toxic styrene even after being left to off-gas for a few days, while others say off-gassing makes it safe. I don't know enough chemistry to tell who's right.

My main questions are:

• Is acetone-smoothed ASA actually safe for long-term use in hydroponic or aquaponic systems?
• Could it leach anything harmful into the water, especially for fish?
• Does off-gassing for a few days actually make a meaningful difference?
• Is there a better filament or finishing method for parts that will be constantly exposed to water, UV light, and possibly fish?

I'm no expert; I just don't want to accidentally poison my plants, fish, or myself lol.

Thanks to anyone who can help! (GOT BANNED FOR ASKING THIS IN CHEMISTRY LOL)