Chapter 5, Problem 5.20P

A device has been designed to measure the flow rate of carbon dioxide evolved from a fermentation reactor. The reactor is sealed except for a tube that allows the generated CO₂ to bubble through a soap solution and into a vertical glass tube with an internal diameter of 1.2cm. On leaving the soap solution, the bubbles form thin soap films stretched across the tube and pushed through the tube by the CO₂. Ambient temperature and pressure arc 27°C and 755 mm Hg. It takes the films 7.4 s to traverse the 1.2m between two calibration marks on the tube.

(a) Sketch the apparatus.

(b) What is the rate of generation of CO₂ in mo1/min?

(c) A more refined analysis of the system takes into account that the gas leaving the fermentation reactor contains water with a partial pressure of 26.7 mm Hg. Calculate the percentage error in

Part (b) using this new information.