Question

The pressure gauge on a tank registers the gauge pres-

sure, which is the difference between the interior and

exterior pressure. When the tank is full of oxygen (O2),

it contains 12.0 kg of the gas at a gauge pressure of

40.0 atm. Determine the mass of oxygen that has been

withdrawn from the tank when the pressure reading is

25.0 atm. Assume the temperature of the tank remains

constant.

Answer 1

$$\frac{m_2}{m_1}=\frac{P_2}{P_1}\\ \frac{m_2}{12}=\frac{25+1}{40+1}\\m_2=7.61\ kg\\ \Delta m=12-7.61=4.39\ m$$