Soru

Zorluk: OrtaPressure Law (Gay-Lussac's Law of Temperature-Pressure)

A rigid steel cylinder contains methane gas at a pressure of 150 kPa150\text{ kPa} and a temperature of 47C47^\circ\text{C}. If the cylinder is heated to 127C127^\circ\text{C} while maintaining a constant volume, what is the final pressure of the gas in kPa\text{kPa}?

Cevap: 187.5 kPa

Cevap

The final pressure of the methane gas is 187.5 kPa187.5\text{ kPa}.
According to Gay-Lussac's Pressure Law, the pressure of a fixed mass of gas is directly proportional to its absolute temperature at constant volume (PTP \propto T). Converting temperatures to Kelvin gives T1=320 KT_1 = 320\text{ K} and T2=400 KT_2 = 400\text{ K}. Applying P1T1=P2T2\frac{P_1}{T_1} = \frac{P_2}{T_2} yields 150320=P2400\frac{150}{320} = \frac{P_2}{400}, which gives P2=187.5 kPaP_2 = 187.5\text{ kPa}.

Adım Adım Çözüm

1
Convert given temperatures to the Kelvin absolute scale.
T1=47+273=320 KT_1 = 47 + 273 = 320\text{ K} and T2=127+273=400 KT_2 = 127 + 273 = 400\text{ K}
All gas law calculations require temperatures to be expressed in Kelvin.
2
Set up the Pressure Law equation relating pressure and absolute temperature at constant volume.
P1T1=P2T2\frac{P_1}{T_1} = \frac{P_2}{T_2}
According to Gay-Lussac's Law, pressure is directly proportional to absolute temperature when volume is fixed.
3
Substitute the known values into the equation and solve for P2P_2.
P2=150×400320=187.5 kPaP_2 = \frac{150 \times 400}{320} = 187.5\text{ kPa}
Cross-multiplication gives P2=187.5 kPaP_2 = 187.5\text{ kPa}.

Anahtar Kavram

Pressure Law (Gay-Lussac's Law)
Bu soruyu puanla