50 ml of Argon is collected at 60.0 degree C and 820.0 torr how much this sample weigh in grams?
Use PV = nRT and solve for n = number of mols. Then n = grams/molar mass and solve for grams. Don't forget T must be in kelvin.
do I need to consider the vapor pressure of Argon at 60.0 degree C
I don't understand your question. The pressure of Ar in the flask is 820 torr. I guess we could call that its vapor pressure.
Remember to convert 820 torr to atm and T to kelvin.
my instructor said we need to use the pressure due to water vapor. i'm confused
Then you didn't post all of the problem. The problem you posted doesn't have any water in it. If you collected the Ar over water and the total pressure is 820 torr, then
Ptotal = 820 = pAr + pH2O
Look up vapor pressure H2O at 60.0 C and subtract from 820 to find pAr.
Then follow the instructions above.
T must be in kelvin
P must be in atm (for PV = nRT)
V must be in L.
To determine the weight of a sample of Argon, 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 gas
R is the ideal gas constant (0.0821 L·atm/(mol·K))
T is the temperature of the gas (in Kelvin)
To use this equation, we need to convert the given values to the appropriate units. Let's start with the temperature:
Given: T = 60.0 degrees C
To convert from Celsius to Kelvin, add 273.15:
T = 60.0 + 273.15 = 333.15 K
Next, let's convert the volume:
Given: V = 50 ml
To convert milliliters (ml) to liters (L), divide by 1000:
V = 50 / 1000 = 0.05 L
Now, we can rearrange the ideal gas law equation to solve for n (moles of gas):
n = PV / RT
Given: P = 820.0 torr
To convert torr to atm, divide by 760:
P = 820.0 / 760 = 1.0789 atm
Lastly, we can plug in the values and solve for n:
n = (1.0789 atm * 0.05 L) / (0.0821 L·atm/(mol·K) * 333.15 K)
Calculating the expression gives us the number of moles of Argon in the sample.
Once we know the number of moles of Argon, we can use the molar mass to convert the moles to grams. The molar mass of Argon is 39.948 g/mol.
So, the weight of the sample of Argon in grams is:
Weight (in grams) = Number of moles x Molar mass
Plug in the values of the number of moles calculated earlier and the molar mass to get the final answer.