The reaction 2 NO(g) + Br2(g) equilibrium reaction arrow 2 NOBr(g) has Kp = 109 at 25°C. If the equilibrium partial pressure of Br2 is 0.0155 atm and the equilibrium partial pressure of NOBr is 0.0763 atm, calculate the partial pressure of NO at equilibrium.

See explanation below

Explanation:

To know this, we need to write again the reaction, and then, write the expression for the equilibrium constant Kp:

2NO + Br₂ <> 2NOBr    Kp = 109

The Kp expression for this reaction is:

Kp = PpNOBr² / PpNO² * PpBr₂

Solving for the NO we have:

PpNO² = PpNOBr² / PpBr₂ * Kp

All we have to do now, is replace the given values:

PpNO² = (0.0763)² / (0.0155) * 109

PpNO² = 3.45x10⁻³

PpNO = √3.45x10⁻³

PpNO = 0.0587 atm