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Homework Help: What is the specific heat of the block?

  1. May 4, 2005 #1
    The specific heat of a 109-g block of material is to be determined. The block is placed in a 34.0-g copper calorimeter that also holds 52.0 g of water. The system is initially at 20.0°C. Then 140 g of water at 83.0°C are added to the calorimeter vessel. When thermal equilibrium is attained, the temperature of the water is 51.0°C. What is the specific heat of the block?

    cu specific heat=.386J/gdegree
    water sh=4.18j/gdegree

    34g(.386J/gdegree)(31degree) + 52g(4.18J/gdegree)(31degree) +
    109g(unknown sh)31degree = 140g(4.18J/gdegree)32degree

    406.844J + 6738.16J + 3379g*degree(unknown sh) = 18726.4J
    3379g*degree(unknown sh) + 7145.004J = 18726.4J
    3379g*degree(unknown sh) = 11581.396J
    unknown sh = 3.42 J/gdegree

    this isnt the correct answer
    thanks for your time
  2. jcsd
  3. May 4, 2005 #2

    Andrew Mason

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    Science Advisor
    Homework Helper

    It is always easier and clearer to work it out algebraically and then plug in numbers. But your work appears to be correct. What is the 'correct' answer?

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