1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Heat enthalpy of molecular hydrogen

  1. Feb 15, 2009 #1
    1. The problem statement, all variables and given/known data
    Look up the enthalpy of formation of atomic hydrogen in the back of the book. This is the enthalpy change when a mole of atomic hydrogen is formed by dissociating 1/2 mole of molecular hydrogen (the more stable state of the element). From this number, determinethe energy needed to dissociate a single H2 molecule , in electron-volts.


    2. Relevant equations
    PV=3100 J
    delta(H)=delta(U)+P*delta(V)
    H=U+PV
    3. The attempt at a solution
    find delta(U)
    delta(U)=delta(H)-P*delta(V)

    found delta(H) to be delta(H)=-217.97 kJ

    According to the standard table T=298 K and P=1 bar=1atm?
    R=8.31 J/K

    PV=RT=(8.31 J/K)(298 K)=2.5 kJ

    H-PV=(-217.97 kJ)-(2.5 kJ)=-220.5 kJ

    Did I find delta(U) correctly?
     
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?



Similar Discussions: Heat enthalpy of molecular hydrogen
Loading...