#1 Science Forum For Lab Technicians

Does anyone know the best (cheap price, fast delivery) place to get sodium alginate and calcium lactate? There are a few places on ebay that sell both in a set but they don't have very good descriptions, just weight totals (eg 100g but is that 50g per packet or 100 per packet?) The experiment calls ...

bigmack wrote: 25 Feb 2026, 22:15 Well not quite , but not far off .
Friday 12 May 2006 first member voice joined .


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HAPPY BIRTHDAY CHEMTALK!!

This is what we do. It's simple and produces a great range of odours.
MAKING ESTERS:
Put approx 2ml of each substance into a large test tube, add approx 15 drops of sulfuric acid (as a catalyst).
Stopper the test tube loosely with cotton wool.
Place the test tube in a large beaker of boiling ...

So good!!

we have 9 benches per room plus the teacher bench so I try to have 10 of everything even though they're rarely all used.

I have put in a purchase request for a pack of 10 strips of 15ml paint pots from Amazon ($18.79) and also a pack of 50x 25ml sauce containers with hinged lids ($11.69) . If it's approved and they fit the dropper holders I will let you all know! If they don't fit, they will still be useful for other ...

I like those ones you posted Rosalie .
Not sure what you mean by being too risky ?

I guess they could melt just as easy as the ones I have if idiot students touch container with a hot wire loop .

Only issue I see is stability , if you knock one , you loose all the chemicals . Just also ...

I just use a cloth or sponge and water. It comes straight of the smooth sections and the rough stuff can just stay black if it doesn't wipe off easily...

While searching, I came across these - Do you think they would be too risky for flame tests? One of each chemical in each pot?

Just wondering what you all use for sending out solid samples to classes? For example, today students are heating copper carbonate so they need little sample pots of that for each group. I generally use small specimen containers which are annoying to store in sets of 10, but today as I was filling ...

I don't think ours get submerged, but we have some with the rubber tipped plunger that just have a ball of plasticine shoved on the squirty end. One has air, one has sand and they do the compression prac with those. I've not had any complaints. It may not suit your purpose though.

Never too late to learn new tricks! Thanks!

Oh and I also did this with metho

Similar topic... but I bought the 20L double strength vinegar from a cleaning supplier a couple of years ago and it's been great! So much cheaper and less waste than buying it from the supermarket in 2L bottles.

How are we going to celebrate?

I got annoyed by the metal ones. I prefer the wooden ones. For most pracs now we use micro test tubes and plastic racks from wiltronics. I have a basket that fits in the dishwasher that i leave on its side and add the test tubes to on their side, and once the test tubes fill the basket I put a gauze ...

Thanks for those links! I will be able to use some of them which is very helpful as a starting point. I forgot to mention it would be a primary school club open to years 2-6, possibly with some yr 9 and 10 agriculture students assisting.

I have found myself in charge of establishing a "sustainability club" which will be starting up next term. Our school already has a worm farm that I have now bought worms for, and I've put a few scrap bins around (staff room, food tech and OOSH for now) and after the holidays we will have larger ...

Yeah we normally do starch in the dialysis tubing and lugol's iodine in the water. The iodine goes in but the starch doesn't come out. The only one group started to turn black.

Does anyone have the prac for glucose osmosis? The one where glucose goes in the tubing and distilled water in the beaker, then test the beaker water for glucose at the end with benedicts solution? The only ones I can find online have the starch and glucose combined (which I will suggest we use for ...