# Chemistry

posted by chemgeek

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.

Still confused...I recalculated and got the w=.006523kJ and the energy change to be -76.82kJ... The energy change is right but the w is wrong for some reason...
I calculated w as w=-delta(n)RT = -(0-.26312molO2)(8.314452x10^-2 Lbarr/molK)(25+273.15) = 6.5226J=.006523kJ...

Thanks

1. DrBob222

Isn't that constant 8.314 and not 0.08314 so you end up with +0.6523 kJ for the work?

2. DrBob222

Let me know how this turns out.

## Similar Questions

1. ### Chemistry

Copper dissolves in nitric acid, producing copper (ll) nitrate. After reaction with sodium hydroxide and heating, copper nitrate changes to copper (ll) oxide. Calculate the percent yield of this process if 1.235 g of copper produced …
2. ### Chemistry

Calculate the standard enthalpy of formation of CuO2, given that: 2Cu2O + O2 ==> 4 CuO (-288 kJ) Cu2O ==> Cu + CuO (11 kJ) PLEASE HELP!!!!
3. ### Chemistry

Can you tell me if these are right please?
4. ### Chemistry

The following reaction has a standard enthalpy of reaction of -146.0 kJ/mol: Cu2O(s) + 1/2 O2(g) -> 2CuO(s) The standard enthalpy of formation of Cu2O(s) is -168.6 kJ/mol. What is the standard enthalpy of formation of CuO(s)?
5. ### Chemistry

I would really appreciate some help with this thermochemistry problem! I'm really confused as to why I keep getting the wrong answers... I have gotten w=-1.305kj and energy change = 78.13kj... both of which were marked wrong. Here's …
6. ### Chemistry

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, …
7. ### Chemistry check and help

so for all the chemical formulas if there is no subscript (for the valency of the element) does it mean it is a one or do i have to find the valency on the periodic table of elements?
8. ### chemistry. please help drbob222

One of the reactions involved in the smelting of copper sulfide ores involves copper (I) oxide and copper (I) sulfide: 2Cu2O2 + Cu2S ---> 6Cu + SO2 Assuming that 35.00 g of copper (I) oxide is heated with 25.00 g of copper (I) sulfide …
9. ### chemistry

The equations for the heats of the formation of copper (I) oxide,Cu2O and copper(II) oxide,CuO are: 2Cu(s) +1/2 O2(g) CuO(s); ∆Hof =-166.7kj/mol Cu(s) +1/2 O(g) CuO(s); ∆Hof= -155.2kj/mol The first and second ionisation …
10. ### Science

1g mixture of Cu2O and CuO on heating gives 0.88g of copper. Calculate % of CuO in mixture

More Similar Questions