What is the total mass (in grams) of O2 in a room measuring (20.0 5.0 11.0) ft3 if the air in the room is at STP and contains 20.95% O2?
Change 20 ft, 5.0 ft, and 11.0 ft to cm, then length x width x height = volume in cubic centimeters (cc) and change that to liters.
32 g x (volume room in L/22.4) = grams if pure oxygen.
Multiply that by 0.2095.
To find the total mass of O2 in the room, we need to follow these steps:
Step 1: Convert the room's volume from ft3 to liters.
1 ft3 is equivalent to approximately 28.3168 liters.
Volume of the room = 20.0 ft3 * 28.3168 L/ft3 = 566.336 L
Step 2: Calculate the number of moles of O2.
To do this, we need to know the molar mass of O2, which is 32.00 g/mol.
Molar mass of O2 = 32.00 g/mol
Since we know that the air in the room contains 20.95% O2, we can calculate the moles of O2 using the percentage composition.
Moles of O2 = 20.95% * 566.336 L * (1 mol/22.4 L) = 4.3035 mol
Step 3: Calculate the total mass of O2.
To find the mass, we can use the formula: mass = moles * molar mass.
Mass of O2 = 4.3035 mol * 32.00 g/mol = 137.712 g
Therefore, the total mass of O2 in the room is 137.712 grams.