mass transfer

A two-bulb system (see Fig 18.2-1) was used measure the diffusivity of ammonia in air. The two bulbs had volumes of 4L, and the capillary connecting them was 12cm in length with a 0.5cm inner diameter. The initial concentrations were 325.0 and 0.0ppm for bulbs 1 and 2, respectively and GC measurements were made on bulb 2 every 5 hours. Using all of the following concentration data for bulb 2, estimate the diffusivity of ammonia in air. Figure 18,2-1. Diffusivity measurement of gases by the two-bulb method