1. Limited time only! Sign up for a free 30min personal 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!

Reduce Melting Temp. by applying Pressure

  1. Jun 3, 2012 #1
    1. The problem statement, all variables and given/known data

    The molar volume of ice at 273.15K and 101.33 kPa is V1=19.6 cm3
    That of water V2=18.00 cm3.
    Latent heat of melting of ice is L=6.0 kJ mol-1.

    Find the pressure that must be applied to reduce the melting point by 1 K.

    2. Relevant equations

    Clausius-Clapeyron

    [itex]\frac{dP}{dT}[/itex] = [itex]\frac{L}{TΔV}[/itex]

    ΔV = (V2-V1)


    3. The attempt at a solution

    The problem I am having is fundamental, this is not the usual find vapour pressure question, which is what caught me off guard. So what I'm asking is a way to set this question up. This is where I've gotten so far.

    [itex]\frac{dP}{dT}[/itex] = [itex]\frac{L}{TΔV}[/itex]

    dP = [itex]\frac{L}{TΔV}[/itex] dT

    P = [itex]\frac{L log (T)}{ΔV}[/itex]

    L log (T) = PΔV

    Log (T) = [itex]\frac{PΔV}{L}[/itex]

    T = exp [[itex]\frac{PΔV}{L}[/itex]]


    Do I subtract 1 from T and solve for P? It doesn't feel right. Or did I completely mess it up?
    If so please show me the set up, I should be ok with the rest.

    Thanks in advance
     
  2. jcsd
  3. Jun 3, 2012 #2

    rude man

    User Avatar
    Homework Helper
    Gold Member

    dp = (L/Δv)dT/T

    then how about computing the definite integral instead of the indefinite one?

    Δp = ?
     
  4. Jun 3, 2012 #3
    *Face Palm* Set limit from (T) to (T-1) I take it. Thanks
     
  5. Jun 3, 2012 #4

    rude man

    User Avatar
    Homework Helper
    Gold Member

    Right. And use the appropriate value of T of course.
     
  6. Jun 3, 2012 #5
    Yup yup! Thanks! I feel a tad retarded for not seeing that.
     
  7. Jun 3, 2012 #6

    rude man

    User Avatar
    Homework Helper
    Gold Member

    Don't. It's always a bit rough the first time you run into a new topic ...
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Reduce Melting Temp. by applying Pressure
  1. Universe's Temp (Replies: 17)

Loading...