Glowing splint test

[HGreig]

Hi

One of the teacher at my school wants to do the glowing splint test and I have no idea what it is or what I need

Please help!

Hayley

[lab-woman]

Hi Hayley,

I think it is the teachers job to tell you exactly what it is and what "they" need. Thats why they are paid the big bucks!!

[AnnNos]

Is that the test for presence of oxygen? We use potassium permanganate and hydrogen peroxide then insert a splint that has been just extinguished and in the presence of oxygen the splint re-ignites (glows)

[Graham Kemp]

Heinemann Science 10 pg 208-209
--Using a Catalyst.
* spatula
* Manganese dioxide (MnO2 or substitute KMnO4)
* 5% Hydrogen peroxide
* glass measuring cylinder
* test tube
* aluminium foil (cap for test tube)
* glowing slplint
* matches

* Place a 1/4 spatula of Manganese dioxide into a test tube.
* Measure 5 mL of Hydrogen peroxide. Pour into the test tube and quickly cover the opening with aluminium foil.
* After a reasonable amount of gas has been collected, and while the reaction is still bubbling, remove the aluminium foil and plunge a glowing splint into the gas in the test tube.
* Record the observations. (Hopefully that the splint will ignite in released oxygen.)

[HGreig]

awesome! thank you so much Im new to all this. where to do i buy hydrogen peroxide from??

Hayley

[RosalieM]

You can usually get 6% (also known as 20vol) at a chemist/pharmacy (we have a "pharmacy warehouse" chain that I get mine from). It is often cheaper than getting it from science suppliers. When you need the stronger stuff though you will need to get it from a supplier.

[HGreig]

thank you

[Loopy]

Hi Fellow Chemtalkers,
Just a question, Hasn't Maganese Dioxide been up graded in Hazard class to causing cancer?

[smiley]

Not sure but here's what is said in RiskAssess:

Potential hazards
Slightly toxic. Can be used safely as a catalyst for the decomposition of hydrogen peroxide solution to produce oxygen gas.

You can't use it to decompose potassium chlorate, which is a no-brainer anyway, since I'm pretty sure that is on the no-go list anyway.

Anyway you're only supposed to use a tiny bit anyway, about this much: []

[Graham Kemp]

Hi Fellow Chemtalkers,
Just a question, Hasn't Maganese Dioxide been up graded in Hazard class to causing cancer?

Well, it was implicated as a reproductive toxin and suspected carcinogen; esp. if it contains crystaline silicate impurities. Handle responsibly.

Not sure but here's what is said in RiskAssess:

Potential hazards
Slightly toxic. Can be used safely as a catalyst for the decomposition of hydrogen peroxide solution to produce oxygen gas.

You can't use it to decompose potassium chlorate, which is a no-brainer anyway, since I'm pretty sure that is on the no-go list anyway.

Oh, yes! That explosive mix is on the banned chemistry list.

[Krysia Lee]

We substitute potassium iodide for manganese dioxide and that works.

[Loopy]

Thanks Smiley. I think I read something in a ChemWatch bulletin. I must go and recheck past issues. Gee, I wish my memory was like it used to be!

[RosalieM]

I'm with lab-woman... Make sure this is what the teacher means!

[DavidPeterson]

Manganese dioxide is still an approved substance here in SA - based on the current (April 2012) DECD Approved Substances & Risk Assessment Register

[Alice]

Here in WA Manganese dioxide is classified hazardous, the dust is not good for you.
We mix the Manganese dioxide with Plaster of Paris, and cut into small pellets when
set. Use 3-4 pellets in a test tube with Hydrogen peroxide. No dust problems or black
powder everywhere!

Alice

[Graham Kemp]

We mix the Manganese dioxide with Plaster of Paris, and cut into small pellets when
set. Use 3-4 pellets in a test tube with Hydrogen peroxide. No dust problems or black
powder everywhere!

Oh, I do like that. It is a rather good idea, Alice.

I might try it out for next time. What ratio of manganese dioxide and plaster do you find best?

[smiley]

Hey yeah we do that too. I've made pellets in the past by mixing 1 teaspoon of MnO2 & a teaspoon of plaster in a little takeaway container. Then I spread out a sheet of cling wrap, and drip little blips of mixture onto the wrap, and let them dry. They kinda look like choc-bits. Great for no-mess reactions.

Thanks for reminding me Alice.

[rae]

Is it recyclable or do you dispose of it when the experiment is done??

[smiley]

Yeah, they pretty much are. And even when they are fairly eroded by H2O2, it minimal amounts one is tossing, and even then they are stabilized by the plaster. I've had the same jar so long, I'd forgotten I had it!

[Alice]

Hi Graeme and everyone

I usually mix half and half Manganese dioxide and Plaster of Paris.
I also spread it over gladwrap and cover it with gladwrap until it is set.
I usually make it about 3mm thick. I cut it with a small chisel into squares.
You can also just break it into pieces, as long as they fit into a flask or
test tube.

Yes, you can reuse it. I just keep it in an airtight jar.

Alice