Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Thermodynamics ethanol Question

  1. Apr 7, 2010 #1
    1. The problem statement, all variables and given/known data
    A student mixes 41.8g of ethanol at 15.8 C with 50.7 g of water at 49.2 C. If the resulting temperature of the solution is 28.4 C, what is the specific heat capacity of the ethanol?


    2. Relevant equations
    Given heat capacity of water already.


    3. The attempt at a solution
    let X = heat capacity of ethanol
    38.4C = (41.8*15.8*X - 49.2*50.7*4.184)/(X*41.8+50.7*4.184)
    i just rearranged and solved for X. I did get the correct answer, however it seems too ugly for a simple MC question.
     
  2. jcsd
  3. Apr 8, 2010 #2

    Borek

    User Avatar

    Staff: Mentor

    I guess 38.4C is meant to be 28.4C. If so it looks OK to me - that is assuming you got signs right, but if the result is correct you probably did. And I am not aware of a simpler method of getting the answer.

    --
    methods
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook