Australia's Science Forum

Hi

teacher has Yr 8 doing this prac this afternoon.

What strength hydrogen peroxide should they use? Will 3% work for them? or better with something stronger?

Thanks
Rita

Ummm. Do you mean Manganese Dioxide? If so then 3% is fine.

In the past I have made cool little Manganese Dioxide pellets by mixing about 1 tablespoon of Plaster of Paris with the same amount of MnO2, and dropping little "blips" of the mixture onto a sheet of gladwrap, about Choc-Bit sized. When they dry, the little blips are useful pellet sized lumps that can be dropped into test tubes with peroxide, and recovered afterwards. Then just dry them out on paper towel and re-use!

Smiley is on the money , manganese dioxide and plaster of paris made into pellets is the way to go (really easy to make). Otherwise the fine manganese dioxide powder gets into everything and is really hard to clean . You just need to make sure that the teachers get students to recycle the pellets. Since the manganese dioxide is only a catalist they can be rinsed, dried and then used again and again (Less money spent and less time spent making more pellets, win win.)

Teacher did mean Manganese dioxide .....like the idea od pellets
thank you

Ok Brains Trust
Quick Question, what do you guys think of a prac which would be
in a large evaporating basin pour in about 1.5cm of Hydrogen Peroxide 35%, slowly add Methlated spirits till it covers abour 1cm then stand back a quickly throw in 1/2 teaspoon of maganese dioxide.

Ok Brains Trust
Quick Question, what do you guys think of a prac which would be
in a large evaporating basin pour in about 1.5cm of Hydrogen Peroxide 35%, slowly add Methlated spirits till it covers abour 1cm then stand back a quickly throw in 1/2 teaspoon of maganese dioxide
Sorry I forgot to mention - Light it then add the Maganese Dioxide

Hello fire department?
Risk assessment??
Teacher demonstration??
Bucket chemistry??
Tell us how it goes.

I asked for a risk assignment, let's see how that goes

I think the thing that concerns me is "stand back and quickly throw". It just sounds like it is all going to end in tears! Yes, definitely a risk assessment needed.

Insanity!
Using 35% peroxide in the first place...NO!