how many moles of O2 would be needed to produce 1120.5 kJ of heat from the reaction:
3Fe + 2O2 yields Fe3O4+ 1120.5 kJ I got 627771.33 which I thought seemed a bit too high. My proportion was 1120.5=2 O2/1120.5.
Thanks again.
Nuts to your calculation. You were given that is the heat of reaction which used 2 moles of 02. Answer: 2 moles of O2
To determine the number of moles of O2 needed to produce 1120.5 kJ of heat from the given reaction, we need to use the stoichiometry of the reaction.
The balanced equation tells us that 3 moles of Fe react with 2 moles of O2 to produce Fe3O4 and release 1120.5 kJ of heat.
We can set up a proportion using the stoichiometric coefficients from the balanced equation:
(2 moles of O2 / 1120.5 kJ) = (x moles of O2 / 1120.5 kJ)
To solve for x, we can cross-multiply and divide:
(2 moles of O2) * (1120.5 kJ) = (1120.5 kJ) * (x moles of O2)
2241 moles·kJ = 1120.5 kJ·moles of O2
Now, we can solve for x:
x moles of O2 = 2241 moles·kJ / 1120.5 kJ
x ≈ 2 moles of O2
Therefore, approximately 2 moles of O2 would be needed to produce 1120.5 kJ of heat from the given reaction.
Your initial calculation of approximately 627771.33 moles of O2 is incorrect because the proportion you set up is not valid. The correct proportion is based on the stoichiometry of the balanced equation.