pillyg Posted February 19, 2011 Share Posted February 19, 2011 This has probably been posted somewhere else, but I couldn't find it. I knew that adding vinegar to Mg would make hydrogen and bubble. I tried it and It made hydrogen just like it was supposed to, but it also made a frothing grey goop. What is this? It seems to be boiling and making some sort of gas. Is it toxic? What is it???? Link to comment Share on other sites More sharing options...
Ralph Posted February 19, 2011 Share Posted February 19, 2011 Magnesium Acetate + Hydrogen Gas Link to comment Share on other sites More sharing options...
pillyg Posted February 20, 2011 Author Share Posted February 20, 2011 OK thanks Link to comment Share on other sites More sharing options...
WSM Posted March 6, 2011 Share Posted March 6, 2011 This has probably been posted somewhere else, but I couldn't find it. I knew that adding vinegar to Mg would make hydrogen and bubble. I tried it and It made hydrogen just like it was supposed to, but it also made a frothing grey goop. What is this? It seems to be boiling and making some sort of gas. Is it toxic? What is it???? This is a classic test for magnesium. Scrap metal dealers use a small dropper bottle with white household vinegar (5%) to test for magnesium vs aluminum (bubbling = Mg, no bubbling = Al). To the trained eye, even MgAl can be detected (less bubbling than Mg, but more than Al). WSM Link to comment Share on other sites More sharing options...
pillyg Posted March 6, 2011 Author Share Posted March 6, 2011 Yeah I was just wondering the chemistry of it and what it made Link to comment Share on other sites More sharing options...
SB15 Posted March 6, 2011 Share Posted March 6, 2011 Mg + 2CH3COOH --> Mg(CH3COO)2 + H2 Classic acid/active metal reaction. Aluminum doesn't undergo the same reaction because the passive Al2O3 layer is impervious to dilute acetic acid at room temperature. Link to comment Share on other sites More sharing options...
Mumbles Posted March 7, 2011 Share Posted March 7, 2011 Aluminum acetate will also probably hydrolyze just about immediately passivating the surface even if you freshly scratch it. If testing a chunk of metal to be Mg or Al, it's probably a good idea to scratch it to get a clean fresh surface to test. The grey froth was probably suspended magnesium particles, some sort of basic salt, or surface grime. Link to comment Share on other sites More sharing options...
pillyg Posted March 7, 2011 Author Share Posted March 7, 2011 Yeah. It seemed like there was 2 different stages of the reaction. The first made small bubbles of H2 and the 2nd made big bubbles of H2 but they were slower. Link to comment Share on other sites More sharing options...
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