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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: nigoe on January 20, 2008, 07:48:16 AM

Title: Reaction mechanism for Magnesium and Acid ?
Post by: nigoe on January 20, 2008, 07:48:16 AM

I was wondering whether there was a general reaction mechanism for the reaction between magnesium and acid. I have read that the order of reaction with respect to Mg is 0. This would imply that the rate determining step is purely to do with Hydrogen (surely the sulfate for instance doesnt take part). In order to show this I need a viable reaction mechanism, any Ideas?

Thanks in advance

Title: Re: Reaction mechanism for Magnesium and Acid ?
Post by: LQ43 on January 20, 2008, 02:32:32 PM

so starting with H2SO4, what happens to the hydrogen in the reaction?

Title: Re: Reaction mechanism for Magnesium and Acid ?
Post by: IITian on January 21, 2008, 12:16:38 PM

I guess one might think of the H₂ evolved being somehow still attached to the Mg surface thereby causing retarded reaction rates!

Title: Re: Reaction mechanism for Magnesium and Acid ?
Post by: LQ43 on January 21, 2008, 10:46:48 PM

Quote from: IITian on January 21, 2008, 12:16:38 PM

I guess one might think of the H₂ evolved being somehow still attached to the Mg surface thereby causing retarded reaction rates!

maybe but unlikely after reduction

molecularity is more likely. 2H+ are need to reduce to H2.

how is H+ produced, what are the chances of 2 H+ getting together on the Mg surface to reduce to H2? how would concentration affect those chances?