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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: canadiankarma on May 04, 2005, 11:44:55 PM

Title: enthalpy of combustion
Post by: canadiankarma on May 04, 2005, 11:44:55 PM
If delta H for the equation for the combustion of magnesium, is -1200kJ/mol, what is the enthalpy of combustion of magnesium?

----Would it be -600kJ/mol since 2 moles of magnesium reacts with 1 mole of oxygen (from the chemical equation)
Title: Re:enthalpy of combustion
Post by: Garneck on May 05, 2005, 02:17:00 AM
Quote from: canadiankarma on May 04, 2005, 11:44:55 PM
If delta H for the equation for the combustion of magnesium, is -1200kJ/mol, what is the enthalpy of combustion of magnesium?

That question is all wrong.

If dH for 2Mg + O2 ---> 2MgO is equal -1200kJ/mol, then yes, the enthalpy of magnesium combustion is -600 kJ/mol for this reaction:

Mg + 1/2 O2 ---> MgO