A sample of Freon-12 (CF2Cl2) occupies 2.507 x 101 L at 291 K and 2.518 x 102 kPa. Find its volume (in L) at standard temperature and pressure (STP).
p1v1/t1 = p2v2/t2
To find the volume of a sample of Freon-12 (CF2Cl2) at standard temperature and pressure (STP), we need to use the ideal gas law equation:
PV = nRT
Where:
P = Pressure
V = Volume
n = moles of gas
R = ideal gas constant (0.08206 L·atm/mol·K)
T = Temperature in Kelvin
To solve for the volume at STP, we need to determine the moles of Freon-12 and then use the ideal gas law equation.
First, let's convert the given temperature from degrees Celsius to Kelvin:
T = 291 K
Next, convert the given pressure from kilopascals to atmospheres:
P = 2.518 x 102 kPa × (1 atm / 101.325 kPa) = 2.4886 atm
Now, we need to calculate the moles of Freon-12 in the sample. To do this, we need to know the molecular weight of Freon-12. The molecular weight (MW) of CF2Cl2 can be obtained from the periodic table or a reliable source. In this case, the molecular weight of CF2Cl2 is approximately 120.91 g/mol.
Next, we can calculate the moles (n) of Freon-12 using the ideal gas law equation, rearranged to solve for n:
n = PV / RT
Substituting the known values:
n = (2.4886 atm) × (2.507 x 101 L) / [(0.08206 L·atm/mol·K) × (291 K)]
n ≈ 2.8977 moles
Now that we have calculated the moles of Freon-12, we can use this information to find the volume (V) at STP. At standard conditions, 1 mole of ideal gas occupies 22.414 L.
V = n × 22.414 L
V ≈ 2.8977 moles × 22.414 L
V ≈ 64.89 L
Therefore, the volume of the sample of Freon-12 at standard temperature and pressure (STP) is approximately 64.89 L.