Page 68 - DJJ20063- Thermodynamics 1
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DJJ20063- Thermodynamics 1



                      Example 2.12


                                                   3
                                                             o
                        A quantity of gas at 0.54 m  and 345  C undergoes a constant pressure process that

                                                                            3
                        causes the volume of the gas to decreases to 0.32 m .  Calculate the temperature of

                        the gas at the end of the process.



                      Solution to Example 2.12

                        From the question
                                  3
                      V1 = 0.54 m
                      T1 = 345 + 273 K = 618 K

                                  3
                      V2 = 0.32 m


                              V 1  =  V 2
                              T 1  T 2

                                         V
                              T 2  = T 1  x   2
                                         V 1

                                               0.32   m 
                                                     3
                                                      
                                       =   (618 K    )    3 
                                               0.54   m  
                                       =   366  K




               2.4.3  Explain the law of ideal gas.



                           Universal Gases Law


                                           PV  = constant  =  R                                  (2.11)

                                           T

                                         P V    P V
                      i.e.                1    1  =  2    2                                        (2.12)
                                          T 1    T 2

                      R- gas constant (Nm/kg K or J/kg K).  Each perfect gas has a different gas constant.


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