Page 80 - DJJ20063- Thermodynamics 1
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DJJ20063- Thermodynamics 1






                                     Feedback To Activity 2F




                      2.14    From the question,

                              m = 2 kg

                              Q = 200 kJ
                                            o
                              (T2 – T1) = 100  C = 373 K


                                       Q = mCv(T2 – T1)

                                              Q         200
                                     C  =            =        =  . 0  268   kJ/kgK
                                       v
                                          m (T  −T  )   ( 2  373 )
                                              2   1




                      2.15    From the question,
                              P1 = 3 bar

                                      o
                              T1 = 315  C = 588 K
                              P2 = 1.5 bar

                              M = 26 kg/kmol

                               = 1.26
                              From equation,

                                          R    8314
                                     R  =  o  =      =  319    8 .  J/kg   K
                                          M     26


                              From equation 2.26,

                                             R      319  8 .
                                     C  =        =         = 1230   J/kg  K   = 1.230   kJ/kg  K
                                       v
                                          ( −   ) 1  . 1  26 − 1
                                           


                              During the process, the volume remains constant (i.e. rigid vessel) for the mass

                              of gas present, and from equation 3.4,

                                       P 1 V 1  =  P 2 V 2

                                       T 1    T 2
                                                                                                 71 | P a g e
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