Agas mixture at 490.0°c and 127 kpa absolute enters a heat exchanger at a rate of 60.0 m3/hr. the gas leaves the heat exchanger at 170.0°c. the change in enthalpy of the gas during the cooling process is -4.70 kj/mol. what is the heat required in kw? assume the gas behaves ideally and that the changes in kinetic and potential energy are negligible.

Explanation:

According to the ideal gas equation, PV = nRT.

or,            n =

As it is given that pressure is 127 kPa or 127000 Pa (as 1 kPa = 1000 Pa), volume is 60.0 , R is gas constant equals 8.314 J/K/mol, and temperature is (490 + 273) K = 763 K.

Hence, putting these values into the above equation as follows.

                    n =

                        =

                        = 0.320 mol/s

Therefore, heat required will be calculated as follows.

  change in enthalpy of the gas during the cooling process × mole flow

                      = 4.70 kJ/mol × 0.320 mol/s

                     = 1.50 kW

Thus, we can conclude that heat required in kW for the given situation will be 1.50 kW.

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