how many grams of propane are in a 35L container at 40 degrees and 900 torr?

PV=nRT

solve for n.
Then multiply n by molmass of propane.

Bob Pursley gave you the same answer I did.

how many grams of propane are in a 35L container at 40 degrees and 900 torr?

To determine the number of grams of propane in a 35L container at 40 degrees and 900 torr, you need to use the ideal gas law equation:

PV = nRT

Where:
P = pressure (in atm)
V = volume (in liters)
n = number of moles
R = gas constant (0.0821 L·atm/mol·K)
T = temperature (in Kelvin)

First, convert the given temperature from Celsius to Kelvin. Add 273.15 to the Celsius temperature to get Kelvin:

40 degrees Celsius + 273.15 = 313.15 Kelvin

Next, convert the given pressure from torr to atmospheres. Divide the pressure by 760 torr (1 atm is equal to 760 torr):

900 torr ÷ 760 torr = 1.184 atm

Now, rearrange the ideal gas law equation to solve for the number of moles:

n = (PV) / (RT)

Substitute the known values into the equation:

n = (1.184 atm x 35 L) / (0.0821 L·atm/mol·K x 313.15 K)

Calculate the result:

n = 0.1667 mol (rounded to four decimal places)

Finally, since propane has a molar mass of approximately 44.1 g/mol, you can determine the mass of propane in grams by multiplying the number of moles by the molar mass:

Mass = n x molar mass
Mass = 0.1667 mol x 44.1 g/mol

The calculation gives you approximately 7.35 grams of propane in the 35L container at 40 degrees Celsius and 900 torr.