what is the relationship between the equilibrium constant Kc and the equilibrium pressure constant Kp? I am given many questions that either give Kc and ask for partial pressures of gases or vice versa. what is the best way to approach these questions? another question states given this equation: SO2 + NO2 --> SO3 + NO Kc=2.9 how much NO2 must be added to 2.2 mol of SO2 to make 1.3 mol of SO3 and equilibrium? I just dont know how to start this. any help would be appreciated. thanks.