M = molar mass of the helium gas = 4.0 g/mol
m = mass of the gas given = 18.0 g
n = number of moles of the gas
number of moles of the gas is given as
n = m/M
n = 18.0/4.0
n = 4.5 moles
P = pressure = 2.00 atm = 2.00 x 101325 Pa = 202650 Pa
V = Volume of balloon = ?
T = temperature = 297 K
R = universal gas constant = 8.314
Using the ideal gas equation
P V = n R T
(202650) V = (4.5) (8.314) (297)
V = 0.055 m³
The volume of balloon is 54.86 L
calculation
The volume is calculated using the ideal gas equation
That is PV=nRT
where,
p= 2.00 atm
V= ?
n( number of moles) which is calculated as below
moles = mass /molar mass = 18.0g / 4 g/mol = 4.5 moles
R ( gas constant) = 0.0821 L. atm / mol.K
T(Temperature) = 297 K
make V the subject of the formula by diving both side by P
V =nRT/P
V= {(4.5 moles x 0.0821 L.atm/mol.K x 297 K) / 2.00 atm} = 54.86 L
