6-39. The air in a 55gal drum must be flushed and inerted with nitrogen before the drum is filled with a flammable liquid. This is accomplished by placing a nitrogen lance through the hole of the drum reaching to the bottom. A constant flow rate of nitrogen is used to achieve the inerting. a. Show that the concentration of oxygen in the drum is represented by VdtdC=kQvC Where C is the concentration of oxygen in the drum (mass/volume), k is the nonideal mixing factor (0.1