[ 497 ] Physical Science GED ® TEST SCIENCE FLASH REVIEW • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Refer to the following passage to answer the next four questions. The Haber process is a chemical reaction where nitrogen and hydrogen gases are combined to form ammonia gas. The reaction is represented by this chemical equation: N 2 (g) + 3 H 2 (g) 2 NH 3 (g) Chemists studied the effects of increasing pressure on the gases in the reaction. The same amounts of nitrogen and hydrogen gases were combined in a fixed chamber. They increased the pressure of the chamber from 0 to 400 atmospheres (atm). They repeated the experiment at several fixed temperatures from 350°C to 550°C. In each case, they measured the percent yield of ammonia produced in the reaction. The data are shown in the graph: 80 70 60 50 40 30 20 10 0 0 100 200 300 400 Pressure (atm) Ammonia Produced (%) 350ºC 400ºC 450ºC 500ºC 550ºC Suppose that you are a chemical engineer and must make a facility that will produce large amounts of ammonia using the Haber process. What would be the best conditions to produce the greatest percent yield of ammonia? ____ atm at ____°C