+ Reply to Thread
Results 1 to 3 of 3

Thread: How do you calculate the standard enthalpy of combustion of diamonds?

  1. #1
    Level 16 - Colossus darni's Avatar
    Joined
    Jan 2012
    Posts
    2,197

    How do you calculate the standard enthalpy of combustion of diamonds?

    How do you calculate if the Enthalpy of formation is 1.895?
    How do you calculate if the Enthalpy of formation is +1.895?

    is it +1.895 or -1.895 for combustion?

  2. Sponsors
    Super ModeratorPeeje's Avatar
    Joined
    Nov 2011
    Posts
    164
    Videos
    139

  3. #2
    Level 1 - Newbie adonai's Avatar
    Joined
    Mar 2012
    Posts
    1,063
    Weee! Diamonds are shiny!

  4. #3
    Level 1 - Newbie gloria's Avatar
    Joined
    Mar 2012
    Posts
    1,138
    i think combustion standard enthalpy is calculated the same as any reaction. if its just standard H u want then its just products - reactants at standard.

    in this case, if you say diamonds H0 is 1.895 then:
    1.895 - 0 (graphite is just carbon in its standard state, right?) = 1.895

    this makes sense since diamonds are highly organized so change in entropy will be very very small meaning with gibs free energy formula
    G = H - TS (delta g, h, s)
    then in order for G to equal 0, H must = TS...S being very small. T would equal 1.895/very very small S = very high temperature T. and we all know diamonds are only formed under very high temperature and pressures. hope that helps =P

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts