Given n2 (g) + 3 h2 (g) 2 nh3 (g), which scenario will allow you to eventually reach an equilibrium mixture involving these chemicals?

The only scenario that will allow you to reach an equilibrium mixture involving these chemicals is to place NH3 into a sealed vessel. This reaction requires pressures between 2100, 3600 psi, and temperatures between 300 and 550 degree Celsius. With this given temperature and pressure, the ammonia naturally decomposes into nitrogen and hydrogen gas at the same rate. When this happen, the concentrations of these chemicals become constant and the system is said to be at equilibrium.