Catalyst reactions

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RosalieL
Posts: 483
Joined: 28 Jan 2021, 13:24
Job Title: Lab Assistant
School: MCS
State/Location: NSW

Catalyst reactions

Post by RosalieL »

Hi all,
Our yr 11s just did a catalyst reaction with Potassium hydrogen tartrate (cream of tartar) and hydrogen peroxide using cobalt nitrate as the catalyst. It didn’t work! We (teacher and I) concluded that the H202 had perhaps decomposed and wasn’t effective. It was an unopened bottle of 35% (I’m pretty sure, otherwise opened only a few weeks ago) but about 12 months old. It didn’t fizz much when poured into the sink. The kids had a 6% solution. We tried it with the 35% and it still didn’t work. In the end we decided to use up the remainder by doing elephants toothpaste and that did work!?? So, any ideas on what went wrong? They watched a video following the same method the kids used so I’m not sure that it was user error. All groups had the same problem. Is there something different with Australian cream of tartar vs American? It is Investigation 13.2 in the Chemistry in Focus books. I have also looked it up in a different edition and it uses potassium sodium tartrate (Rochelle salt). Is the cream of tartar one a mistake? I will have to check if the video used the potassium hydrogen tartrate or the potassium sodium tartrate…

Happy to hear any theories, no matter how wild they sound!
Merilyn1
Posts: 1476
Joined: 12 Mar 2013, 08:10
Job Title: Labbie
School: Wollondilly Anglican College
Suburb: Tahmoor
State/Location: NSW

Re: Catalyst reactions

Post by Merilyn1 »

Not sure if it helps, but the supermarkets used to sell Tartaric Acid along with Cream of Tartar. They are different, but can't remember why!
My HT uses tartaric acid when making sherbet, not cream of tartar.
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