A 3.00- L
flask is filled with gaseous ammonia, NH3
. The gas pressure measured at 20.0 ∘C
is 2.05 atm
. Assuming ideal gas behavior, how many grams of ammonia are in the flask?
Express your answer to three significant figures and include the appropriate units.
To solve this problem, we can use the ideal gas law equation:
PV = nRT
where:
P = pressure (in atm)
V = volume (in L)
n = number of moles
R = ideal gas constant (0.0821 L*atm/mol*K)
T = temperature (in Kelvin)
First, we need to convert the temperature from Celsius to Kelvin:
T(K) = 20.0 + 273 = 293 K
Now we can rearrange the ideal gas law equation to solve for the number of moles:
n = (PV) / (RT)
n = (2.05 atm * 3.00 L) / (0.0821 L*atm/mol*K * 293 K)
n ≈ 0.2508 mol
Now we can calculate the molar mass of ammonia (NH3):
N = 14.01 g/mol
H = 1.01 g/mol
Therefore, the molar mass of NH3 = 14.01 g/mol + 3(1.01 g/mol) = 17.03 g/mol
Now we can calculate the mass of ammonia in the flask:
mass = number of moles * molar mass
mass = 0.2508 mol * 17.03 g/mol = 4.27 g
Therefore, there are approximately 4.27 grams of ammonia in the flask.