Taking into account the Gay Lussac's law, the pressure in the backup tank at -183 °C is 270 mmHg.
Gay Lussac's law establishes the relationship between the temperature and pressure of a gas when the volume is constant.
This law says that the pressure of the gas is directly proportional to its temperature: when there is a constant volume, as the temperature increases, the pressure of the gas increases. And when the temperature is decreased, gas pressure decreases.
Mathematically, Gay-Lussac's law states that the ratio between pressure and temperature has the same value:
[tex]\frac{P}{T} =k[/tex]
Studying an initial state 1 and a final state 2, it is fulfilled:
[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]
In this case, you know:
Replacing in the Gay-Lussac's law:
[tex]\frac{900 mH}{300 K} =\frac{P2}{90 K}[/tex]
Solving:
[tex]P2=90K\frac{900 mH}{300 K}[/tex]
P2=270 mmHg
Finally, the pressure in the backup tank at -183 °C is 270 mmHg.
Learn more about the Gay-Lussac's law:
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