Answer:
0.1575 atm
Step-by-step explanation:
we have that equilibrium constant Kp = (PNO)₂PO₂ / (PNO₂)₂
and it is given to be 158
==> Kp = (PNO)₂PO₂ / (PNO₂)₂ = 158
we also have that the partial pressure of O2 (PO₂) = 0.99 atm
Therefore,
PO₂ = 0.99 atm ==> PNO = 2(0.99 atm) = 1.98 atm (based on the stoichiometry)
==> PNO₂ = √((PNO)₂PO₂ / 158) atm = √((1.98)*2(0.99) / 158) atm = 0.1575 atm