3. Ammonia (NH3) gas is produced from a reaction and collected over water at a t
ID: 556009 • Letter: 3
Question
3. Ammonia (NH3) gas is produced from a reaction and collected over water at a temperature of 21 °C. During collection, the apparatus is aligned so that the level of water inside the collection vessel is equal to the level of water outside the collection vessel. The atmospheric pressure of the lab is 763 mmHg. The volume of the gas collected was measured to be 24 mL Find the pressure of the ammonia collected. Calculate the mass of ammonia collected Analyze the effectiveness of the lab set up. Was this a valid way to determine the amount of ammonia produced? Reference intermolecular forces in your answer. a. b. c.Explanation / Answer
a)
Pammonia = Ptotal - Pvapor
Pvapor (21°C) = 18.7
Pammonia = 763 - 18.7 = 744.3
b)
PV = nRT
n = PV/(RT) = (744.3*0.024)/(62.4*(21+273))
n = 0.000973704 mol of ammoni
mass = mol*MW = 0.000973704*17
mass f NH3 = 0.016552968 g = 16.55 mg of NH3
c)
this is most likely correct, since NH3 is not quite soluble in water at low T