A 1-\rm L flask is filled with 1.35 g of argon at 25 {\rm ^\circ C}. A sample of ethane vapor is added to the same flask until the total pressure is 1.15 atm.What is the partial pressure of argon, P_Ar, in the flask?What is the partial pressure of ethane, P_ethane, in the flask?
Assuming 1-\rm L flask means 1L flask and 25{\rm^\circ C} means 25 degrees C, then
Use PV = nRT to find the partial pressure of Argon. You know n = grams/atomic mass, R, T, and V. Solve for P.
Then use Ptotal = Pethane + PAr to solve for Pethane.
I have asked repeatedly what \rm means and what {rm^\circ} means with no response at all. If we don't know the symbols you use, perhaps we are giving the wrong answers.
To Dr. Bob, those are font codes for a chemistry homework website, MasteringChemistry . com The students are copy and pasting the questions directly and not proofreading.
ex 1-/rm L means 1L, when on the site, the L is in a different font. And 25{\rm^\circ C} means 25 (the degree bubble) C
To find the partial pressures of argon (P_Ar) and ethane (P_ethane) in the flask, we need to use the ideal gas law, which relates the pressure (P), volume (V), number of moles (n), and temperature (T) of a gas.
The ideal gas law equation is given by:
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.
First, let's calculate the number of moles of argon in the flask using the given mass of argon and its molar mass.
1. Calculate the number of moles of argon:
Given mass of argon = 1.35 g
Molar mass of argon (Ar) = 39.95 g/mol
Number of moles of argon (n_Ar) = (mass of argon) / (molar mass of argon)
n_Ar = 1.35 g / 39.95 g/mol
Next, we need to find the number of moles of ethane added to the flask. However, we are not given the mass or any other information about the ethane sample. Therefore, we cannot directly determine the number of moles of ethane.
However, we know that the total pressure in the flask is 1.15 atm. Using Dalton's law of partial pressures, we can conclude that the sum of the partial pressures of argon and ethane equals the total pressure of the mixture.
P_total = P_Ar + P_ethane
Since we now know the total pressure and the value of P_Ar (which we're trying to find), we can rearrange the equation to solve for P_ethane:
P_ethane = P_total - P_Ar
Substituting the given values:
P_total = 1.15 atm
To calculate the partial pressure of argon (P_Ar), we need to determine the number of moles of argon (n_Ar). Once we know n_Ar, we can use the ideal gas law to solve for P_Ar.
Now let's proceed to calculate P_Ar:
1. Convert the temperature from Celsius to Kelvin:
Given temperature = 25 °C
Temperature in Kelvin (T) = (temperature in Celsius) + 273.15
T = 25 °C + 273.15
2. Rearrange the ideal gas law equation to solve for pressure (P) and substitute the values:
PV = nRT
Pressure (P_Ar) = (number of moles of argon) * (ideal gas constant) * (temperature in Kelvin) / volume of flask
P_Ar = (n_Ar * R * T) / V
Since V is given as 1 L, we can substitute the above values into the equation:
P_Ar = (n_Ar * R * T) / 1 L
Finally, substitute the values of n_Ar, R, and T into the equation, and calculate the partial pressure of argon:
P_Ar = (n_Ar * 0.0821 atm L/mol K * T) / 1 L
Please provide the temperature in Kelvin to further calculate the value of the partial pressure of argon (P_Ar) and ethane (P_ethane).