Liquid propane is flowing through a 6-nom galvanized iron pipe at a flow rate of 3 kg/s. The average temperature of the propane in the pipe is 0°C.

a. Determine the convective heat transfer coefficient inside the pipe.

b. Determine the convective heat transfer coefficient for the C2–C10 hydrocarbons, ethane, propane [Part (a)], butane, pentane, hexane, heptane, octane, nonane, and decane, for the same conditions as described in the problem.
Plot the convective heat transfer coefficient vs. the number of carbon atoms in the fluid. Can you suggest an explanation for the trend seen in the plot?