Specific Heat Problems Specific Heat Answers Problems 


Solutions to Specific Heat Problems



q = (m)(Dt)(cp)   where q  is the energy in joules
                                          m is the mass
                                          Dt is the change in initial temperature to the final temperature
                                          cp is the specific heat (heat required to raise 1 g of the substance 1C)

 

1) q = (m)(Dt)(cp)
     2.5 x 103 J = (1.0 x 104 g)(70C-10C)(cp)

    [2.5 x 103 J]                 = cp
     [1.0 x 104 g][70C-10C]

     0.0042 J    =  cp
                  gC

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2) qmetal = (m)(Dt)(cp)      qwater = (m)(Dt)(cp)

     qmetal  =  qwater

        (m)(Dt)(cp)    =     (m)(Dt)(cp)

      [1.0Kg][100C-Tf][0.50KJ]  =  [50.0g][Tf-20C][4.184 J]
                                   [   KgC]                                 [      gC ]

      [1.0Kg][1000g][100C-Tf][0.50KJ][   1Kg][1000J]  =  [50.0g][Tf-20C][4.184 J]
                   [   1Kg]                 [   KgC][1000g][   1KJ]                                [      gC ]

       [1000g][100C-Tf][0.50J]  =  [50.0g][Tf-20C][4.184 J]
                                    [   gC]                                [      gC ]

      [1000g][100C-Tf][0.50   J/gC]  = [Tf-20C]
       [ 50.0g]                [4.184 J/gC]

       [2.39][100C-Tf]  =  [Tf-20C]

       239C-2.39Tf  =  Tf-20C

       239C + 20C  =   T+  2.39Tf  

       259C  =  3.39Tf

       259C  =  Tf
         
3.39

        76C  =  Tf     

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3) 

qmetal = (m)(Dt)(cp)      qwater = (m)(Dt)(cp)

     qmetal  =  qwater

        (m)(Dt)(cp)    =     (m)(Dt)(cp)

      [2.80Kg][100C-Tf][0.43KJ]  =  [50.0g][Tf-30C][4.184 J]
                                     [   KgC]                                 [      gC ]

      [2.8.0Kg][1000g][100C-Tf][0.43KJ][   1Kg][1000J]  =  [50.0g][Tf-30C][4.184 J]
                      [   1Kg]                 [   KgC][1000g][   1KJ]                                [      gC ]

       [2800g][100C-Tf][0.43J]  =  [50.0g][Tf-30C][4.184 J]
                                    [   gC]                                [      gC ]

      [2800g][100C-Tf][0.43   J/gC]  = [Tf-30C]
       [ 50.0g]                [4.184 J/gC]

       [24.08][100C-Tf]  =  [Tf-30C]

       2408C-24.08Tf  =  Tf-30C

       2408C + 30C  =   T+  24.08Tf  

       2438C  =  25.08Tf

       2438C  =  Tf
         
325.08

        97C  =  Tf    

 

 

Specific Heat Problems