Problem: Calculate Kp for each of the following reactions: N2(g) + O2(g) ⇌ 2NO(g); Kc = 4.10 x 10–31 (at 298 K)

We are being asked to calculate K_p for the reaction:

N₂(g) + O₂(g) ⇌ 2NO(g)

When dealing with equilibrium:

• K_c → equilibrium units are in molarity 
• K_p → equilibrium units in terms of pressure

Kp and Kc are related to one another by the following equation below: 

$\boxed{{\mathbf{K}}_{\mathbf{p}}\mathbf{=}{\mathbf{K}}_{\mathbf{c}}{\left(\mathbf{RT}\right)}^{\mathbf{∆}\mathbf{n}}}$

R = gas constant = 0.08206 (L∙atm)/(mol∙K)
T = temperature, K
Δn = moles of gas products – moles of gas reactants

Calculate K_p:

Given:                        K_c = 4.10 x 10^–31 
                                   T = 298 K

Reaction:

N₂(g) + O₂(g) ⇌ 2NO(g)

reactants = 2 moles gas