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Help - confusion :( The oxidation of copper(I) oxide, Cu2O(s), to copper(II) oxide, CuO(s), is an exothermic process,
2 Cu2O + O2 --> 4CuO The change in enthalpy upon reaction of 75.30 g of Cu2O(s) is -76.83 kJ. Calculate the work, w, and energy change, ΔUrxn, when 75.30 g of Cu2O(s) is oxidized at a constant pressure of 1.00 bar and a constant temperature of 25°
c.
Here's my line of reasoning.. but it's been marked wrong. Thank you in advance.
converting 75.3g of Cu2O to moles of CuO, I got 1.0525mol CuO
W=-delta(n)RT = -(1.0525mol)(8.3144J/molK)(25+273.15)= -2.609 kJ
energy change = -2.609kj+ - 76.83kJ = -79.439kJ

Respuesta :

Hagrid
This is the answer for the question above:

In order to solve this, first use stoichiometry for the energy in kJ released by, converting grams of CuO2 to moles: 

56.96g*(1 mole/143.09 g)=0.41904 moles of Cu2O 

2 moles of Cu2O=-292.0kJ Convert 0.41904 moles of Cu2O to kJ. 


Finally, solve for kJ: 

0.41904 moles of Cu2O*(-292.0kJ/2 moles of Cu2O)=-61.18 kJ of energy released

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