A 1.00 L flask is filled with 1.05 g of argon at 25 ∘C. A sample of ethane vapor is added to the same flask until the total pressure is 1.150 atm .
a.)What is the partial pressure of argon, PAr, in the flask?
b.)What is the partial pressure of ethane, Pethane, in the flask?
To find the partial pressure of argon (PAr) and ethane (Pethane) in the flask, we can use Dalton's law of partial pressures, which states that the total pressure of a gas mixture is equal to the sum of the partial pressures of each individual gas.
a.) Partial pressure of argon (PAr):
Since we know the total pressure of the gas mixture is 1.150 atm and want to find the partial pressure of argon, we first need to find the partial pressure of ethane (Pethane).
From Dalton's law of partial pressures:
Total pressure = Partial pressure of argon + Partial pressure of ethane
Substituting the given values, we have:
1.150 atm = PAr + Pethane
b.) Partial pressure of ethane (Pethane):
To find the partial pressure of ethane, we need to subtract the partial pressure of argon (PAr) from the total pressure.
From the equation above:
Pethane = Total pressure - PAr
Now, let's calculate the values.
First, we need to convert the mass of argon (1.05 g) and the temperature (25 °C) to moles and kelvin, respectively.
1 mole of any gas occupies 22.4 L at standard temperature and pressure (STP), which is 0 °C or 273.15 K.
Converting the given temperature:
25 °C + 273.15 = 298.15 K
Now, let's calculate the number of moles of argon:
1.05 g of argon / (39.95 g/mol) = 0.0263 mol
Since the volume of the flask is 1.00 L, we can assume it is constant, meaning the number of moles of the gas mixture (argon + ethane) is constant.
Thus, the number of moles of ethane added to the flask is:
Total moles - Moles of argon = Total moles - 0.0263 mol
Now, let's consider the ideal gas law to find the partial pressure of ethane:
PV = nRT
Where:
P is the partial pressure of ethane (Pethane)
V is the volume of the flask (1.00 L)
n is the number of moles of ethane
R is the ideal gas constant (0.0821 L·atm/mol·K)
T is the temperature in Kelvin (298.15 K)
Rearranging the equation:
Pethane = (nethane * R * T) / V
Since we know the total pressure is 1.150 atm, we can use the equation from part a to find the partial pressure of argon.
1.150 atm = PAr + Pethane
Now you can solve these equations to find the values of PAr and Pethane.
so used Dalton's Law. I will be happy to critique your thinking.
It does no good to post a series of test questions using different names, none of which indicate any work on your part.