A 1-L flask is filled with 1.25g of argon at 25 ∘C. A sample of ethane vapor is added to the same flask until the total pressure is 1.35atm .
What is the partial pressure of argon, PAr, in the flask?
What is the partial pressure of ethane, Pethane, in the flask?
Use PV = nRT and solve for pAr. n = grams Ar/atomic mass Ar.
Then Ptotal = 1.35 atm = pAr + pethane
To find the partial pressure of argon, we need to calculate it using the ideal gas law equation, PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.
Step 1: Convert the given mass of argon to moles.
To convert the mass of argon to moles, we need to use the molar mass of argon, which is 39.95 g/mol.
molar mass of argon = 39.95 g/mol
mass of argon = 1.25 g
number of moles of argon = mass of argon / molar mass of argon
number of moles of argon = 1.25 g / 39.95 g/mol
Step 2: Convert the temperature from Celsius to Kelvin.
The temperature is given in Celsius, and we need to convert it to Kelvin. The Kelvin temperature is equal to the Celsius temperature plus 273.15.
temperature = 25 ºC
temperature in Kelvin (T) = 25 ºC + 273.15
Step 3: Calculate the partial pressure of argon.
We are given the total pressure in the flask, which is 1.35 atm. Since we are interested in the partial pressure of argon, we need to subtract the partial pressure of ethane from the total pressure.
partial pressure of argon (PAr) = total pressure - partial pressure of ethane
Now, let's calculate the partial pressure of argon (PAr).
partial pressure of argon (PAr) = ?
Step 4: Calculate the partial pressure of ethane.
To find the partial pressure of ethane, we can subtract the partial pressure of argon from the total pressure.
partial pressure of ethane (Pethane) = total pressure - partial pressure of argon
partial pressure of ethane (Pethane) = ?
Now, let's calculate the partial pressure of ethane (Pethane).
Let's start by calculating the number of moles of argon.
number of moles of argon = 1.25 g / 39.95 g/mol
temperature in Kelvin (T) = 25 ºC + 273.15
partial pressure of argon (PAr) = 1.35 atm - Pethane
partial pressure of ethane (Pethane) = 1.35 atm - PAr
Let's calculate the number of moles of argon and the partial pressure of argon.
To find the partial pressures of argon (PAr) and ethane (Pethane) in the flask, we need to use the ideal gas law equation:
PV = nRT
Where:
P = Pressure
V = Volume
n = Number of moles
R = Ideal gas constant
T = Temperature in Kelvin
To find the partial pressure of argon (PAr):
1. Convert the temperature from Celsius to Kelvin:
T = 25 °C + 273.15 = 298.15 K
2. Calculate the number of moles of argon:
nAr = massAr / molar massAr
Since the mass is given as 1.25g and the molar mass of Ar is 39.948 g/mol:
nAr = 1.25g / 39.948 g/mol
3. Calculate the partial pressure of argon using the ideal gas law equation:
PAr = nArRT / V
Since the volume (V) is given as 1 L and the ideal gas constant (R) is 0.0821 L·atm/mol·K:
PAr = (nAr * 0.0821 * 298.15) / 1
To find the partial pressure of ethane (Pethane):
1. Calculate the number of moles of ethane added to the flask.
2. Since the total pressure is 1.35 atm, we can subtract the pressure of argon from the total pressure to get the pressure due to ethane:
Pethane = Ptotal - PAr
Now that we have the equations and steps, you can input the values and calculate the answers.