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)

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