A balloon is filled with helium to a volume of 1050 L on the ground, where the p
ID: 514715 • Letter: A
Question
A balloon is filled with helium to a volume of 1050 L on the ground, where the pressure is 745 mmHg and the temperature is 20 degree C. A) Calculate the amount (in mol) of helium in the balloon. Just give the number to 3 significant figures. There is ___________ mol of helium in the balloon B) Calculate the volume (in L) of helium when the balloon ascends to a height of 2 miles, where the pressure is on 600 mmHg and the temperature is -33 degree C. Just give the number to 3 significant figures. The volume is _________ LExplanation / Answer
A.PV = nRT
P = 745mmHg = 745mmHg/760mmHg/atm = 0.98atm
V = 1050l
T = 20C = 20+273 = 293K
R = 0.0821Latm/molK
PV = nRT
n = PV/RT
= 0.98atm*1050l/0.0821Latmmol-1K-1*293K
n = 1029.28/24.0553 mol
n = 42.8mol
B.P = 600mmHg = 600/760 = 0.789atm
T = -33C = -33+273 = 240K
V = ?
n = 42.8mol
R = 0.0821latm/molK
PV = nRT
V = nRT/P
= 42.8mol*0.0821latm/molK *240K/0.789atm
V = 1069L