Calculate the weight of ethane, C2H6 (MWT = 30g/mole), required to produce a pressure of 1520 mm at 20 degrees C when contained in a 9.00 liter vessel. How many moles of ethane is it?
22.46 which rounds to 22.5 to 3 s.f. For n I obtained 0.7486 which rounds to 0.749 moles. I used 2.00 for P, 9.00 for V. 0.08206 for R and 293 for T.
To solve this problem, we need to use the ideal gas law equation:
PV = nRT
where:
P = pressure (in atm)
V = volume (in liters)
n = number of moles
R = ideal gas constant (0.0821 L·atm/mol·K)
T = temperature (in Kelvin)
First, we need to convert the pressure from mmHg to atm:
1520 mmHg ÷ 760 mmHg/atm = 2 atm
Next, we need to convert the temperature from degrees Celsius to Kelvin:
20°C + 273.15 = 293.15 K
Now we can rearrange the ideal gas law equation to solve for the number of moles (n):
n = PV / RT
Substituting the values we have:
n = (2 atm) * (9.00 L) / (0.0821 L·atm/mol·K) * (293.15 K)
Calculating this expression will give us the number of moles of ethane required to produce the given pressure and temperature in the given volume.
Use PV = nRT and solve for n = number of moles.
Then moles = grams/molar mass. Solve for grams.