MATERIALS SCIENCE AND ENGINEERING DEPARTMENT 2014-2015 FALL MSE 309- PHASE DIAGRAMS HOMEWORK-II 1-A plain carbon steel with 0.6 % carbon is heated in a CO+CO2 gas mixture at 700oC and 1 atm pressure. Temperature is high enough for the following reactions to take place under equilibrium conditions: C+CO2 = 2CO Fe3C = 3Fe + C a) b) c) d) How many chemical species are present in the system? How many components are there in the system? How many phases are there in the system? Apply the phase rule principle and discuss what you find. 2-The vapor pressure of liquid zinc as a function of temperature is given by the expression: log P (mmHg) = (-6620/T) – 1.255logT+12.34 Calculate the heat of vaporization of zinc at its boiling point 907oC. 3-The vapor pressure equation for solid cadmium is: log P (mmHg) = -5908/T-0.232logT+9.717 The melting temperature of cadmium is 321oC and its enthalpy of fusion is 1543 cal/mole. a) Derive an equation which gives the vapor pressure of liquid cadmium as a function of temperature b) What is the normal boiling temperature for cadmium? c) Determine the triple point temperature of this metal (R=8.314 J/mole-K, loge10=2.303, Atomic weights: Pb=207, Cd=112 gr/mole) Pressure conversions 760 mmHg = 1 atm 1 bar = 0.9872 atm 1 bar = 105 Pa (N/m2) Due 16.10.2014