Rates of reaction - kinetics
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In an investigation of ativation energy between acid and magnesium I got a value of about 20 kJ/mol for HCl and 40 kJ/mol for H2SO4. I thought these should much more similar as the basic reaction of metal and H+ is the same for both reactions. is there any chemical explanation for this difference?
Your reasoning makes sense. The question is whether or not the value you have got for sulphuric acid is correct. If you look at Activation energy: what answer did you get? among the tutorials in Practical Investigations on this web site you will see that not many have reported results for Mg and sulphuric acid. Some have, however, and their results are generally closer to 20 kJ/mol than to 40 kJ/mol.
So you need to check your value before looking for explanations for it being so much higher than for HCl.
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updated: 21 April 2004
