J.R. S. answered 12/04/23
Ph.D. University Professor with 10+ years Tutoring Experience
2NO(g) + O2(g) ==> 2NO2(g)
Approach: find moles of NO in large bulb, and find moles O2 in the small bulb by using the ideal gas law:
PV = nRT and n = PV/RT
moles NO = (0.650 atm)(6.00 L) / (0.0821 Latm/Kmol)(295K) = 0.161 mols NO
moles O2 = (2.50 atm)(1.50 L) / (0.0821 Latm/Kmol)(295K) = 0.155 mols O2
Next, determine which reactant is limiting:
From the mol ratio in the balanced equation, we see that NO is limiting as it takes 2x the mols of O2.
Set up an ICE table to determine moles of each gas at equilibrium:
2NO(g) + O2(g) ==> 2NO2(g)
0.161......0.155.............0..............Initial
-0.161....-0.0805..........+0.161......Change
0........0.0745...........0.161........Equilibrium
These values are the moles of each gas present at equilibrium. To convert to partial pressure, we first find total volume (7.50 L) and and then use ideal gas law to determine pressure of each:
PV = nRT and P = nRT/V
Pressure of O2 = (0.0745 mol)(0.0821 Latm/Kmol)(295K) / 7.50 L = 0.241 atm
Pressure of NO2 = (0.161 mol)(0.0821 Latm/Kmol)(295K) / 7/50 L = 0.520 atm
Pressure of NO = 0 atm, as all of it is consumed in the reaction