Calculate Qv from Qp: deltaH and deltaU

[aruhland]

Homework Statement

For the reaction below, constant pressure heat of reaction is Qp=-2051 kj/mol at 25 C. What is the constant volume heat of reaction, Qv, at 25 C?

10CO(g) + 21H2(g) --> C10H22(l) + 10 H2O(l)

Relevant Equations

enthalpy change=internal energy change + change in mol=*R*T
internal energy change=Qv-Pext*volume change

Qp=deltaH
Qv=deltaU
deltaH=deltaU + deltanRT
Qv=deltaH - deltanRT
=-2051 kj/mol - (11mol-31mol)(8.3145x10-3J/Kmol)(298.15K)
=-2001.42 kJ/mol

I thought I did this correctly but it comes up as wrong for my online assignment. Any suggestions?

deltaH=enthalpy change
deltaU=internal energy change

 

[Chestermiller]

Check your algebra

 

[mjc123]

What is Δn? Change in number of moles of gas...