Sciencemadness Discussion Board

K2SO4: catalyst for elephant toothpaste?

bbartlog - 4-7-2011 at 20:06

It's claimed in several places on the web that K2SO4 can be used as a catalyst for the 'elephant's toothpaste' chemistry demo. I did this earlier today with my kids and K2SO4 doesn't seem to work - at least, what I think is K2SO4 obtained from wood ashes doesn't do anything. I got the demo to work using CuSO4+NaOH as a catalyst, but I'm wondering whether there is any basis to the notion that K2SO4 would catalyze the decomposition of H2O2.

#maverick# - 4-7-2011 at 20:26

yeast can be used as a catalyst and with yeast you can add a fluorescent dye to make glow in the dark, this wont work with KI i dont remember why though

barley81 - 5-7-2011 at 16:44

Apparently iodide ions quench fluorescence, check out this video:
http://www.youtube.com/watch?v=hjhLaMrHiLQ
I have no idea how this works, but it's pretty cool and may be suitable for a demonstration.

LanthanumK - 6-7-2011 at 03:04

When I did my science project on catalytic decomposition of H2O2 by various metal salts, I do not remember Na2SO4 as decomposing it very fast. K2SO4 should be slightly faster but still relatively slow.