# Course:ENPH257/Archive/2017St1/Assignments/06

### Assignment #6 for marking[edit | edit source]

1. Consider an methanol fuel cell:

CH3OH + oxygen -> liquid water +…

(a) From enthalpy and entropy data available on the web, calculate ΔH and ΔG for this reaction at room temperature and pressure. Calculate values per mole and per kg. (b) What is the voltage of the cell?

2. Using the barymetric equation and the dry adiabatic lapse rate Γd, make a simple finite difference calculation to find the rate of the change of pressure and density with altitude. Start at 15 C and 101 kPa. What is the scale height (where the pressure is 1/e of the sea level value).

**Make sure that you indicate your answers appropriately, e.g. "The RMS velocity of air at 273K is v_rms = ... ".**

Email your homework to mailto:enph257@phas.ubc.ca

Submit ONE pdf file, named **ENPH257_A6_yourfamilyname.pdf** by 08:30am Tuesday July 4th.

If you are one of the Lins or Wilsons, append the initial of your given name to the filename.