Given Ka values of 5.76×10^-10 & 4.8×10^-10, for NH4+ anf HCN.what is the equilibrium constant for following reaction? NH4+ + CN- >< NH3 + HCN
To find the equilibrium constant for the given reaction, you can use the concept of stoichiometry and the relationship between equilibrium constants.
The reaction you provided is:
NH4+ + CN- ⇌ NH3 + HCN
First, you need to write down the balanced chemical equation and identify the stoichiometric coefficients. From the equation, you can see that the stoichiometric coefficients for NH4+, CN-, NH3, and HCN are 1, 1, 1, and 1, respectively.
The equilibrium constant expression (Kc) is written as follows:
Kc = [NH3][HCN] / [NH4+][CN-]
Now, we need to substitute the equilibrium concentrations of each species into the equation using the given Ka values.
Let's assume the initial concentration of NH4+ is "x" M, and the initial concentration of CN- is also "x" M, according to the balanced equation.
At equilibrium, the concentration of NH3 will be "x" M, and the concentration of HCN will also be "x" M, as there is a 1:1 stoichiometric relationship between them.
Therefore, we can rewrite the equilibrium constant expression as:
Kc = [x][x] / [x][x]
Simplifying this equation, we get:
Kc = (x * x) / (x * x)
Kc = 1
So, the equilibrium constant (Kc) for the given reaction NH4+ + CN- ⇌ NH3 + HCN is equal to 1.
It's worth mentioning that the Ka values provided for NH4+ and HCN are not directly used to calculate the equilibrium constant of the reaction. Ka values are used to determine the acid dissociation constants for individual species in a solution, which can be helpful in understanding the strength of acids and their relative equilibrium positions.