Australia's Science Forum

Hi Everyone! Just wondering what you all do with solid chemicals that have been mixed up. My little bottles of chemicals for flame tests are all messed up with who knows what in them. I don't know how it is so hard to rinse the loop before each dip (since that is part of the process anyway - wet the loop!) but obviously it is too hard for some... so I am starting afresh (using ideas found here!) but I don't know what I should do with all the contaminated ones.
Rosalie

Do you have a container in the lab for heavy metal waste?
I would put it in there.
btw I was at the uni recently and they were doing flame tests for Science in the Bush.
They had the metals (aqueous solns) in small beakers with a paddle pop stick soaking in each.
I was impressed with that idea and am thinking about ditching the spray bottles we currently use.

Yeah I introduced the paddle pop flame test version this year and the students and teachers love it. So much easier to use.

We are converted.

I trialled the paddlepop idea which I am planning to go with from now on. That's why I'm quite happy to be getting rid of these samples. Thanks JudyM - didn't consider the heavy metals container! It collects the liquids but of course I can throw the solids in there too! I'm suffering from end of year brain shut-down I think...

with the paddle pop stick method, make sure you soak the stick in distilled water first, so it doesnt ignite.
we use toothpicks for this prac.

I tried to paddle pop sticks this year but did not work that well. What concentration of solutions do people use? I used 0.1M chlorides but the teachers said that they did not show the colours very well.

I've been using the paddle pop method for years and love it! I soak the sticks over night in water and the students then dip it into the sample container that has about 0.5g of the solid metal chloride. Get great results.

I have saturated solutions made up and when a prac is required I pour about 20 mls into small labelled beakers . I then top up my sat solutions with water ready for the next prac. This has lasted me all year. No complaints just praise which is nice.

We have changed from paddlepop sticks which the little darlings would proceed to burn, to using unfolded paper clips. Just wet them and dip in the crystals. Work well.

Dime - that is essentially what we used to do but with wire loops. It took no time for them to contaminate the little bottles. Even when we tried the paper clips ("New paper clip each time") they still managed to mix them up!

dime wrote:We have changed from paddlepop sticks which the little darlings would proceed to burn, to using unfolded paper clips. Just wet them and dip in the crystals. Work well.

I'm quite lucky, my girls don't leave them in long enough to burn. I can count the number of burnt ones on one hand over the course of 5-6 years that we have been doing it this way.