Equilibrium Constant
Chemical reaction :
\(\ce{aA + bB <=> cC + dD}\) where molecules A,B,C,D are the reactants and products of the reaction and a,b,c,d are the coefficients of molecules A, B, C, D.
Equilibrium constant formula : `K_c = \frac{[C]^c*[D]^d}{[A]^a*[B]^b}` [A], [B], [C], [D] are the concentrations of A, B, C and D in mol per liter.
Do not enter molecules symbols like SO2, H2 ... Enter data separated by space(s).Powers of 10 : input 2.5*10^-3 or 2.5e-3 for [A] = `2.5*10^(-3)` mol/l
This tool calculates the equilibrium constant for a chemical reaction.
We consider the following chemical reaction :
\(\ce{aA + bB <=> cC + dD}\)
A and B are the reactants.
C and D are the products.
a and b are the reactant coefficients.
c and d are the product coefficients.
The equilibrium constant is calculated as follows,
`K_c = \frac{[C]^c*[D]^d}{[A]^a*[B]^b}`
[A]: Molar concentration of reactant A in mol per liter (mol/l)
[B]: Molar concentration of reactant B in mol per liter (mol/l)
[C]: Molar concentration of product C in mol per liter (mol/l)
[D]: Molar concentration of product D in mol per liter (mol/l)
Example of use
This is the chemical reaction of ammonia synthesis:
\(\ce{N2 + 3H2 <=> 2NH3}\)
There are 2 reactants which are nitrogen and hydrogen and one product, ammonia.
Reactants:
A = `N_2`
B = `H_2`
The product:
C = `NH_3`
Coefficients:
a = 1
b = 3
c = 2
Then, the following values should be entered in the form:
- Field "Coefficients of Reactants" : 1 3
- Field "Coefficients of Products" : 2
If we suppose the equilibrium molar concentrations are (in mol/l):
[`N_2`] = 0.03
[`H_2`] = 0.09
[`NH_3`] = `1.7*10^(-8)`
Then, we should enter the following values in the calculator:
- Field "Reactant concentrations (mol/l)": 0.03 0.09
- Field "Product concentrations (mol/l)": 1.7e-8
That leads to the following calculator: `Kc = 1.32*10^(-11)`
See also
Conversion of molar concentration units
Ionic Force Calculator
Solution and Equilibrium Calculators
Chemistry Calculators