Question

Show all work please! Thank you!

1. In a stirred tank fermentation, sparingly soluble gas (usually oxygen) is sparged into a liquid; if there is initially no gas present in the stirred liquid, the time-dependent concentration of the dissolved gas (Cgas) can be fit to the following equation: gas -Cgas (1-ekt) where ku is a mass transfer coefficient, t is time, and C as is the equilibrium concentration of dissolved gas. Below are three different experimental runs where the dissolved oxygen 96(DO%; percentage of equilibrium dissolved oxygen) is plotted as a function of time. Time [s] | D0% (run 1) | DO% (run 2) | DO% (run 3) 5 10 15 20 25 7996 17.72% 322996 14.79% 13.06% 24.42% 343096 27.39% 38.12% 47.27% 55.07% 61.71% 67.37% 7 2.20% 79.81% 442996 54.16% 62.28% 68.96% 74.46% 78.99% 85.77% 34. 30% 42.88% 50.34% 56.83% 62.47% 67.37% 175.34% 30 35 40 50 1 For run 1, linearize the equation and determine the mass transfer coefficient k in units of h a, b. Determine the mean and standard deviation of k in unit of h. The next three questions deal with a tank of laughing gas comprising 70% mole nitrous oxide (NA) and 30% mole 02. What is the percent by mass of oxygen in a gaseous mixture whose molar composition is 20.00% laughing gas and 80.000% air? The composition of air is 21% mole O2, 79% mole N2, and has an average molar mass of 29.0 g/mol. A laughing gas tank was inadvertently left open in a dentist's office over the weekend at a flow rate of 1.4 mol/min. The concentration of N20 in the room cannot exceed 14% by mole or people will not be able to work (without laughing). Determine the minimum rate that fresh air has t the total amount of gas in the room is constant, and that no N,0 was in the room before the leak 2. 3.

Answer 1