Agas mixture at 535.0°c and 109 kpa absolute enters a heat exchanger at a rate of 67.0 m3/hr. the gas leaves the heat exchanger at 215.0°c. the change in enthalpy of the gas during the cooling process is -5.00 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.

the heat rate required to cool down the gas from 535°C until 215°C is -2.5 kW.

Explanation:

assuming ideal gas behaviour:

PV=nRT

therefore

P= 109 Kpa= 1.07575 atm

V= 67 m3/hr = 18.6111 L/s

T= 215 °C = 488 K

R = 0.082 atm L /mol K

n = PV/RT = 109 Kpa = 1.07575 atm * 18.611 L/s /(0.082 atm L/mol K * 488 K)

n= 0.5 mol/s

since the changes in kinetic and potencial energy are negligible, the heat required is equal to the enthalpy change of the gas:

Q= n* Δh = 0.5 mol/s * (- 5 kJ/mol) =2.5 kW

c (diamond),

sio2 (quartz)