Sulfamic Acid

[merilyn]

We bought a kit for Briggs-Rauscher Oscillating Reaction. It is made up of sulfamic acid, potassium iodate, malonic acid and manganese sulfate. It is quite fun to do - cycles from pale orange to dark purple and back again. We want to buy the individual chemicals but I cannot find any supplier of sulfamic acid (except for 5 tonnes from China - just don't think that's what the HT was after!)

Any one ever bought this? Anyone interested in sharing 5 tonnes - I'll only need about 100g

[Whspa]

Serrata has Sulphamic acid LR 500 gm $43.48 (ex GST) in their 2010 Chemical list.

[lada]

Could you, please give me the method? Sounds a good fun

Lada

[linotas]

Yes please share

[merilyn]

Thanks, couldn't find it on Serrata's website, probably mispelt it. Seems that sometimes it is spelt with an "f" and sometimes "ph". I can give you the "recipe", but I've found some of the chemicals are expensive eg malonic acid is $98 for 100g. The kit cost $19 from Prof Bunsen and we've done about 15 individual experiments and we still have about half left.
The kit came with tiny scoops, prob smaller than 0.5mL, sorry haven't had time to measure properly, so if you can work around that, here's the rest: 1. Two 50mL beakers, one labelled "A", the other "B"
2. dissolve half a scoop of sodium iodate and 1 level scoop of sulfamic acid in 10mL water in beaker "A"
3. In beaker "B" add 10mL hydrogen peroxide. Then add 1 rounded scoop malonic acid and a small amount of manganese sulfate about the size of a grain of sand. Add 3-4 drops of starch solution and mix.
4. Add "A" to "B" and swirl together.

Stand back and be amazed!

[lada]

Thanks Merilyn!!!

Lada

[merilyn]

Sorry, forgot to add: it's 3% hydrogen peroxide

[kjt]

We do the Briggs-Rauscher oscillating clock but do not use sulfamic acid. We use the method found at:

http://chemistry.about.com/cs/demonstra ... 50204a.htm

Works well and the kids love it!