A gaseous mixture contains 413.0 Torr of H2(g), 372.1 Torr of N2(g), and 70.1 Torr of Ar(g). Calculate the mole fraction, X, of each of these gases.
Ptotal = pH2 + pN2 + pAr
XH2 = pH2/Ptotal
XN2 = pN2/Ptotal
XAr = par/Ptotal
I don't know why this posted again. Sorry and I have some questions. How do I find the Ph2 and PN2?
Hello Dr. Bob, I'm also having issues with a similar problem. I was able to calculate the XAr, but am unable to find the correct answers for H2 and N2, can you please help this Blake kid and I out? My book shows no problems of this sort, in order for me to work out and i'm unable to find anything else on the internet other than Blake's other post which you replied you had already helped out. What am I missing here? I've tried dividing the numbers by 2 multiplying them by 2. I've tried multiplying my atm conversions from Torr for H2 and N2 by the Ptotal. I cannot seem to figure out where I'm going wrong. Thank you for your time Sir. I do greatly appreciate your help!
To calculate the mole fraction (X) of each gas in the gaseous mixture, we need to use the formula:
X = n_gas / n_total
Where:
- X is the mole fraction of the gas
- n_gas is the number of moles of the gas
- n_total is the total number of moles of all gases in the mixture
To calculate the mole fractions, we first need to calculate the number of moles for each gas. We can do this using the ideal gas law:
PV = nRT
Where:
- P is the pressure of the gas
- V is the volume of the gas
- 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 in Kelvin
We are given the pressure for each gas in Torr. However, to use the ideal gas law, we need to convert the pressure to atm. 1 atm = 760 Torr.
Let's convert the pressures to atm and calculate the number of moles for each gas:
For H2:
P(H2) = 413.0 Torr = 413.0 / 760 atm = 0.5434 atm
n(H2) = (P(H2) * V) / (R * T)
Similarly, for N2:
P(N2) = 372.1 Torr = 372.1 / 760 atm = 0.4891 atm
n(N2) = (P(N2) * V) / (R * T)
And for Ar:
P(Ar) = 70.1 Torr = 70.1 / 760 atm = 0.0922 atm
n(Ar) = (P(Ar) * V) / (R * T)
Once we have calculated the number of moles for each gas, we can calculate the total number of moles:
n_total = n(H2) + n(N2) + n(Ar)
Finally, we can calculate the mole fraction of each gas using the formula mentioned earlier:
X(H2) = n(H2) / n_total
X(N2) = n(N2) / n_total
X(Ar) = n(Ar) / n_total
By following these steps, you should be able to calculate the mole fraction of each gas in the given gaseous mixture.