Exactly 5.02 grams of an unknown gas was sealed in a 3.0L flask at 37 degrees celsius and a pressure of 1.25 atm. Which on of the following is most likely to be the unknown?
I am not sure how to start this.
Use PV = nRT and solve for n.
Then n = grams/molar mass. Solve for molar mass.
Compare with molar masses of the gases listed in the answer choices.
ok so I did (1.25)(3.0) = n(0.0821)(310)
3.75 = n(25.451)
n=0.1473
Then I did 0.1473= 5.02/mm but I am not sure if this is right.
To determine the unknown gas, we can use the Ideal Gas Law equation:
PV = nRT
Where:
- P is the pressure of the gas (in atm)
- V is the volume of the gas (in liters)
- n is the number of moles of the gas
- R is the ideal gas constant (0.0821 L·atm/mol·K)
- T is the temperature of the gas (in Kelvin)
First, we need to convert the given temperature from Celsius to Kelvin. To do this, we add 273.15 to the Celsius temperature:
37 °C + 273.15 = 310.15 K
Now that we have the values for pressure (P), volume (V), and temperature (T), we need to calculate the number of moles (n) using the formula:
n = (PV) / (RT)
Substituting the given values:
n = (1.25 atm * 3.0 L) / (0.0821 L·atm/mol·K * 310.15 K)
n ≈ 0.150 mol
Now, we have the number of moles of the unknown gas. We can use the molar mass of each gas option and the number of moles to determine the gas with a mass of 5.02 grams.
Compare the molar masses of the gases with the calculated number of moles. Multiply the molar mass by the number of moles to find the mass of each gas option:
Molar mass (g/mol) × Number of moles = Mass of gas (g)
The gas option that results in a mass closest to 5.02 grams is most likely to be the unknown gas.