Heat Capacities: ConcepTest and Example Problem

Try to answer this ConcepTest and solve the example problem before using this module. Studies show that trying to answer the questions before studying material improves learning and retention. We suggest that you write down the reasons for your answers. By the end of this module, you should be able to answer these on your own. Answers will be given at the end of this module.

Example Problem 1

A mixture of 70.% benzene and 30.% toluene at 150°C and a flow rate of 540 mol/h is fed to a furnace. What is the outlet temperature if 22 MJ/h are added to the mixture? The heat capacity coefficients, which can be used from 273 to 1500 K are in the table.

\(Molecule\) \(A\) \(Bx10^2\) \(Cx10^5\) \(Dx10^9\)
Benzene
-36.193
-48.444
-31.548
77.753
Toluene
-34.364
88.8887
-34.435
80.335

\(C_P = A + BT + CT^{2} + DT^{3}\) 

where \(C_P\) is in J/mol-K and T is in kelvin.