Question

Deborah has 33 g of H2 in a balloon. The pressure inside the balloon is 1.87 atm and the temperature inside the ballon is 25 Celsius. What's is the volume of the balloon? (Celclius should be converted to Kelvin)

Answer 1

We use the ideal gas law PV = nRT, where:
• P is the pressure of the gas,
• V is the volume of the gas,
• n is the amount of substance of gas (in moles),
• R is the universal gas constant,
• T is is the absolute temperature of the gas (in kelvins).
P = 1,87 atm = 1,87 × 101325 Pa = 189477,75 Pa;
n = m/M; M = 2 g/mol;
n=33/2=11,5 mol;
R = 8,314 m3⋅Pa⋅K-1⋅mol-1;
T = 273,15 + t = 273,15 + 25 = 298,15 K
V = nRT/P = 11,5⋅8,314⋅298,15/189477,75 = 0,15 m-3 = 150 L.

Answer:
V = 150 L.