Created By : Rina Nayak

Reviewed By : Phani Ponnapalli

Last Updated : Apr 03, 2023


By taking the help of Kp Calculator, you will get the exact equilibrium constant using the partial pressures or convert between Kc and Kp. You have to select the either calculate Kp from partial pressures or convert between Kp and Kc based on your requirement, fill the input fields and tap the calculate button to obtain the answer in seconds.

I want to:
Partial pressure of A component:
Coefficient: a
Partial pressure of B component:
Coefficient: b
Partial pressure of C component:
Coefficient: c
Partial pressure of D component:
Coefficient: d
Equilibrium constant(Kp):

How to Calculate Kp from Kc?

Go through the steps to convert K p and K c.

  • Obtain the equilibrium constant Kc, temperature, no of moles of products and reactants.
  • Get the difference between moles of products and reactants.
  • Multiply the gas constant with the temperature.
  • Find the product to the power of the above difference.
  • Again multiply it with the constant to get Kp.

Steps to Calculate Equilibrium Constant Kp from Partial Pressures

  • Get the partial pressures, coefficients of both reactants and products.
  • Find the partial pressure to the power of every substance.
  • Multiply the resultants of reactants and products.
  • Divide the value of the products by the reactants to check the equilibrium constant.

What is the Equilibrium Constant Kp?

Equilibrium is a state that occurs in reversible reaction where forward and backward reactions happen simultaneously.

If the equilibrium constant is calculated using the partial pressures called Kp. If it is calculated using molar concentration is called Kc.

The reversible reaction is a[A] + b[B] ⇌ c[C] + d[D]

The equilibrium constant in terms of molar concentration is

Kc = ([C]c * [D]d) / ([B]b * [A]a)

The equilibrium constant in terms of partial pressures is

Kp = (Pcc * Pdd) / (Pbb * Paa)

Where,

[A], [B] are the molar concentrations of reactants

[C], [D] are the molar concentrations of the products

Pa and Pb are partial pressures of the reactants

Pc and Pd are partial pressures of the products

The relation between the Kp and Kc is provided here:

Kp = Kc * (R * T) Δn

where

Kp is the equilibrium constant in terms of pressure

Kc is the equilibrium constant in terms of molarity

R is the gas constant

T is the temperature

Δn is the change in the number of moles:

Δn = mol of gaseous products - mol of gaseous reactants

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FAQ’s on Kp Calculator

1. What is Kp?

In chemical reactions, when two or more reactants participate in the chemical reaction to get the products and products will again get the reactants called the reversible reaction. If you can calculate the equilibrium constant using the molar constant (Kc) or by using partial pressure is Kp.


2. What is the relationship between Kc and Kp?

For a reversible chemical reaction c[c] + d[D] ⇌ a[A] + b[B], the relstionship between the equilibrium constants Kp and Kc is given here:

Kp = Kc(RT)(c+d)-(a+b).


3. What are the applications of the equilibrium constant?

The equilibrium constant K p applications are listed here:

  1. The equilibrium constant is used for predicting the extent of reaction
  2. It is used for predicting the direction of a reaction

4. What is the formula to calculate Kp from partial pressures?

The equilibrium constant Kp formula is Kp = (Pcc * Pdd) / (Pbb * Paa). Here Pc, Pb are the partial pressures of reactants and Pc, Pd are the partial pressures of products.


Equilibrium Constant(Kp) Calculator