156k views
0 votes
The shark tank at an aquarium houses 5 sharks that deplete the aquarium water of a total of 80.00 g of oxygen per hour. Water from the tank is diverted through a bubbler unit that oxygenates the water using a stream of oxygen-rich air, and then is returned to the tank. At steady state, water enters the bubbler containing 0.000700 wt% 0_2 and exits the bubbler containing 0.001000 wt% 0_2. For every kilogram of the inlet water stream that enters the bubbler, 0.00500 mol of oxygen-rich air with an initial composition of 35.00 mole% 0_2 and 65.00 mole% N_2 is fed through the bubbler. Label the flowchart of the process below. Drag the labels below to fill in the spaces next to each quantity. If for a quantity, place the word "unknown" in the space. DO NOT LEAVE ANY SPACES EMPTY. *SCROLL BELOWTO SEE THE REST OF THIS PROBLEM.* How many unknowns are there in this process? Number What independent equations/relations can you write for this process? Check all that apply. The sum of the weight fractions of the inlet water stream equals 1. The sum of the weight fractions of the outlet water stream equals 1. The sum of the mole fractions of the outlet air stream equals 1. Material balance for water. Material balance for 0_2. Material balance for N_2. 80.00 g/hr of 02 is added to the water via the bubbler. For every kilogram of water that enters the bubbler, 0.00500 mol of air enters the bubbler. 80.00 g/hr of 02 leaves the bubbler in the outlet water stream. How many degrees of freedom are in this process? Number

1 Answer

2 votes

The labels for the flowchart are not provided, so I am unable to complete that part of the question. However, I can answer the other questions:

Number of unknowns:

There are 3 unknowns in this process:

1. The flow rate of water entering the bubble

2. The flow rate of water leaving the bubbler

3. The flow rate of oxygen-rich air entering the bubbler

Independent equations/relations:

1. The applicable independent equations/relations are:

2. The sum of the weight fractions of the inlet water stream equals 1.

3. The sum of the weight fractions of the outlet water stream equals 1.

4. The sum of the mole fractions of the outlet air stream equals 1.

5. Material balance for water.

6. Material balance for O2.Material balance for N2.

Degrees of freedom:

The degrees of freedom can be calculated using the formula:

degrees of freedom = number of unknowns - number of independent equations/relations

degrees of freedom = 3 - 6 = -3

Since the degrees of freedom is negative, it means that the system is over-constrained, which is expected for a well-defined process.

User Inemanja
by
8.1k points