Question

The pollutant NO is formed in diesel engines. The reaction fixes atmospheric nitrogen with oxygen to form NO. The reaction is: N2(g) + O2(g) = 2NO(g). If the equilibrium constant for this reaction at elevated temperatures is 5.60E-11, then what is the partial pressure of NO gas if nitrogen is 1.50 atm and oxygen is 0.500 atm? The units are atmospheres.

Answer 1

I assume you mean you START with pN2 = 1.50 atm and START with pO2 = 0.5 atm?

..........N2 + O2 ==> 2NO
I........1.50..0.5.....0
C.........-x....-x.....2x
E.......1.50-x..0.5-x...2x

Substitute the E line into K expression and solve for x, and the othr values.

Answer 2

BTW, just a reminder that THERE ARE NO UNITS in Kp, Kc, Ksp, Keq, etc. I know some profs use units (some because they don't know better) and if they call them provisional units that makes it ok, but technically, activities go in those constants and activities don't have units so K can't have units.