A 10.0-ft3 compressed-air tank is being filled. Before the filling begins, the tank is open to the atmosphere. The reading on a Bourdon gauge mounted on the tank increases linearly from an initial value of 0.0 to 100 psi after 15 seconds. The temperature is constant at nOF, and atmospheric pressure is 1 atm. (a) Calculate the rate h(lb-mole/s) at which air is being added to the tank, assuming ideal gas behavior. (Suggestion: Start by calculating how much is in the tank at t = 0.) (b) Let N(t) equal the number of lb-moles of air in the tank at any time. Write a differential balance on the air in the tank in terms of N and provide an initial condition. (c) Integrate the balance to obtain an expression for N(t). Check your solution two ways. (d) Estimate the number of lb-moles of oxygen in the tank after two minutes.
Spencer Kociba CHEM 101 Lecture notes Lecture 09/27/16 ● Physical Properties ○ Intensive physical property= does NOT depend on the amount of matter in substance ■ Ex. odor, color, melting/freezing point, density ○ Extensive physical property= DOES depend on the amount of matter in a substance ■ Ex. mass, weight, volume, length ○ Chemical property=quality that can only be established by changing a substance’s chemical identity (ex. Gasoline into carbon dioxide) ○ Physical property= used to describe the original composition of a substance (ex. Gasoline is clear
