Kc to Kp Calculator

Formula

To calculate the conversion from Kc to Kp:

$Kp = Kc \times (RT)^{\Delta n}$

Where:

$Kp$ is the equilibrium constant in terms of pressure
$Kc$ is the equilibrium constant in terms of concentration
$R$ is the ideal gas constant (0.0821 L·atm/(K·mol) or 8.314 J/(K·mol) depending on the units used)
$T$ is the temperature in Kelvin (K)
$\Delta n$ is the change in moles of gas in the reaction (calculated as moles of gaseous products – moles of gaseous reactants)

What is Kc to Kp?

Kc to Kp refers to the conversion from the equilibrium constant in terms of concentration (Kc) to the equilibrium constant in terms of pressure (Kp) in the context of chemical reactions. This conversion is necessary because some reactions are better described by the pressure of the reactants and products, while others are better described by their concentrations. The relationship between Kc and Kp is given by the equation $Kp = Kc(RT)^{\Delta n}$ , where $R$ is the ideal gas constant, $T$ is the temperature in Kelvin, and $\Delta n$ is the change in moles of gas in the reaction.

Example Calculation 1

Let's assume the following values:

Kc = 0.5
R = 0.0821 L·atm/(K·mol)
T = 298 K
Δn = 1

Using the formula:

$Kp = 0.5 \times (0.0821 \times 298)^{1} = 12.239$

The equilibrium constant (Kp) is 12.239.

Example Calculation 2

Let's assume the following values:

Kc = 2.0
R = 0.0821 L·atm/(K·mol)
T = 350 K
Δn = -1

Using the formula:

$Kp = 2.0 \times (0.0821 \times 350)^{-1} = 0.069$

The equilibrium constant (Kp) is 0.069.