A rigid, insulated tank whose volume is 10 L is initially evacuated. A pinhole leak develops and air from the surroundings at 1 bar, 25 C enters the tank until the pressure in the tank becomes 1 bar (assume ideal gas model k=1.4 for the air). Find: A) final temperature in tank.
B) amount of air that leaks into tank in grams.
C) amount of entropy produced in J/K.

The answer is ""

Explanation:

For point a:

Energy balance equation:

From the above equation:

because the rate of air entering the tank that is constant.

Since the tank was initially empty and the inlet is constant hence,

Interpolate the enthalpy between . The surrounding air  

temperature:

Substituting the value from ideal gas:

Follow the ideal gas table.

The and between temperature

Interpolate

Substitute values from the table.

For point b:

Consider the ideal gas equation.  therefore, p is pressure, V is the volume, m is mass of gas. (M is the molar mass of the  gas that is and R is gas constant), and T is the temperature.

For point c:

 Entropy is given by the following formula:

increase masses, decrease separation