A helium baloon has a volume of 28.9L, what is the mass of helium inside the ballon? what is the mass of the same volume of air it displaces? MM of air = 29.0g/mol, 25C (temperature) and 1 atm.
Use PV = nRT and solve for n = moles He. then moles = grams/molar mass. Solve for grams He.
mass air = moles air x molar mass air.
To find the mass of helium inside the balloon, we need to know the molar mass of helium. The molar mass of helium is approximately 4.0 g/mol.
To calculate the mass of helium in the balloon, we'll use the ideal gas law equation: PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant, and T is temperature.
From the given information, we know:
Volume of the balloon (V) = 28.9 L
Molar mass of helium (MM of He) = 4.0 g/mol
First, we need to calculate the number of moles (n) of helium in the balloon using the ideal gas law equation:
PV = nRT
Rearranging the equation to solve for n:
n = (PV) / (RT)
Now let's substitute the given values:
P = 1 atm
V = 28.9 L
R = 0.0821 L·atm/mol·K (the ideal gas constant)
T = 25°C = 298 K
n = (1 atm * 28.9 L) / (0.0821 L·atm/mol·K * 298 K)
Simplifying the equation:
n = 1.193 mol
Now we can calculate the mass of helium inside the balloon by multiplying the number of moles (n) by the molar mass of helium (MM of He):
Mass of helium inside the balloon = n * MM of He = 1.193 mol * 4.0 g/mol
Mass of helium inside the balloon ≈ 4.77 g
Now, to find the mass of the same volume of air that the balloon displaces, we can use the ideal gas law again. The molar mass of air is given as 29.0 g/mol.
Using the same equation:
n = (PV) / (RT)
Substituting the values:
P = 1 atm
V = 28.9 L
R = 0.0821 L·atm/mol·K
T = 25°C = 298 K
n = (1 atm * 28.9 L) / (0.0821 L·atm/mol·K * 298 K)
Simplifying the equation:
n ≈ 1.193 mol
The mass of the same volume of air that the balloon displaces is given by multiplying the number of moles (n) by the molar mass of air (MM of air):
Mass of air displaced = n * MM of air = 1.193 mol * 29.0 g/mol
Mass of air displaced ≈ 34.597 g
Therefore, the mass of helium inside the balloon is approximately 4.77 g, and the mass of the same volume of air it displaces is approximately 34.597 g.