Question

If a 10. m3 volume of air (acting as an ideal gas) is at a pressure of 760 mm and a temperature of 27 degrees Celsius is taken to a high altitude where the pressure is 400. mm Hg and a temperature of -23 degrees Celsius, what volume will it occupy? (Hint: remember the temperature must be in Kelvin)

Answer 1

16. m3

Explanation:

27 degrees Celsius= 27+273= 300 kelvin

23 degrees Celsius= -23+273=250 kelvin

Combined Gas Law: P1V1/T1 = P2V2/T2

(760mm*10 m3)/300 K=(400mm*x m3)/250 K x= 16. m3

The volume that it will occupy is 16. m3.

(Don't forget the sig fig, 15.83--->16. because the question said 10.)

Answer 2

From the combined gas law
P1V1/T1 = P2V2/T2, Where P1, V1 and T1 are the initial pressure, volume and temperature respectively, while P2,V2 and T1 are the new pressure, volume and temperatures respectively.
Thus; P1= 760 mmHg, V1=10 m^3, T1 = 27 +273 = 300 K
P2= 400 mmHg, V2= ? and T2= -23 +273 = 250K
V2 = (P1V1T2)/T1P2
= (760×10×250)/(300×400)
= 1900000/120000
= 15.83
Therefore, the new volume is 15.83 m³