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!

Temperature change boiling water

  1. Dec 11, 2005 #1
    An iron cylinder is heated to 100.degrees C in boiling water ant then transferred to 145.0 grams of water in a 70.0 gram copper calorimeter at 20.0 degrees C. If the final temperature is 25.2 degrees C find the mass of iron used.

    Would I use mL(Boiling water)+mcT(water)+mcT(coper calorimeter) +mcT (iron)???

    And what would be negative?
     
  2. jcsd
  3. Dec 11, 2005 #2

    Astronuc

    User Avatar

    Staff: Mentor

    The iron will lose heat, so its temperature must decrease from 100°C to Tf = 25.2°C.

    The 145 grams of water and the 70 g of copper in the calorimeter will experience a temperature increase from 20°C to Tf = 25.2°C.
     
  4. Dec 11, 2005 #3
    Ok so is that the right equation because it keeps giving me a negative
     
  5. Dec 11, 2005 #4

    Astronuc

    User Avatar

    Staff: Mentor

    Try, mc[itex]\Delta{T}[/itex](water)+mc[itex]\Delta{T}[/itex](copper calorimeter) +mc[itex]\Delta{T}[/itex] (iron) = 0.

    The boiling water has nothing to do with the heat transfer. The only significant factor as far as boiling water is concerned is that the iron is heated to 100°C.
     
  6. Dec 11, 2005 #5
    Ok so I've got (.1450)(4.186)(5.2) +(.070)(.85)(5.2) +(m)(.44)(-74.8)Which gives me 8.8194=2.912m and m=.255kg
    So the iron cylinder is going to have more mass than the water and the calorimeter????
     
  7. Dec 11, 2005 #6

    Astronuc

    User Avatar

    Staff: Mentor

  8. Dec 11, 2005 #7
    Oops! so (.1450)(4.186)(5.2) +(.070)(.385)(5.2) +(m)(.44)(-74.8) which gives me 3.296384=32.912m which gives the mass to be .100kg this makes more sense thanks!!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?