Hydrogen Peroxide

[Krysia Lee]

HI
I'm about to do the elephants toothpaste prac, has anyone done this heating the perioxide in the microwave first so to compare it with cold perioxide. If you have how long did you heat it for and how much. Please and thank you

[RosalieM]

I just sat it in hot water. I don't think I'd be brave enough to put it in the microwave.

[Krysia Lee]

Thanks Rosalie, I was in a hurry so popped it in the microwave for 40 seconds, worked well.

[Jen2]

So is the reaction heaps better???
We always heat our diet coke when doing the mentos demo to get a higher fountain, but I never thought of heating the H2O2 for elephants toothpaste. We always get such a huge amount of foam, I'm a bit scared to think how much would come shooting out if the reaction was sped up.
Would love to know the comparison of hot and cold H2O2.

[Ocker]

I would think as you heated peroxide it would give off it's extra O becoming warm water
That's why I store my H2O2 in fridge

[Graham Kemp]

I would think as you heated peroxide it would give off it's extra O becoming warm water
That's why I store my H2O2 in fridge

It decomposes into water and oxygen gas at above 80°C; or earlier in the presence of catalists: metals, acids, oxidisable organic materials, etc.

Heating is rather contraindicated.

[RosalieM]

It's only heated immediately before the experiment. I usually have a second bottle that I only put as much as I want to use in to heat it. I keep the rest in the fridge.

[smiley]

I heat it up to varying temps. Too hot and it just explodes in one big whoosh with not enough bubbles. Impressive, and made a cool iodine stain on the ceiling. So yes, we played one year with some Senior Chem kids and found optimum temps and dilutions. 50% carpet cleaning super dooper H2O2 is crazy, but fun!

[Krysia Lee]

So I did heat it gently in the microwave for only 30 seconds and it was 56 degrees when I got it out.There really wasn't much of a difference between the hot and cold. The cold one as expected kept producing foam longer. We did this a rate of reaction prac where the variable was temperature so we got the result we wanted. The kids really liked it.

[Ocker]

My kids do their own prac while soil testing they allow the end of the dropper to touch the soil than screw the dropper back on the bottle
Next morning I find all the dropper teat are blown up like a balloon or burst
Beautiful children!!!!!!!!!!!!!!!!!!!!

[RosalieM]

why do they use it for soils?

[Ocker]

Test for organic matter!

[RosalieM]

oh really? we don't do that here. What's the story? If it bubbles there is organic matter?

[Ocker]

right