Answer:
Kb = 1.77x10⁻⁵
Explanation:
When NH₃, a weak base, is in equilibrium with waterm the reaction that occurs is:
NH₃(aq) + H₂O(l) ⇄ NH₄⁺(aq) + OH⁻(aq)
And the dissociation constant, Kb, for this equilibrium is:
Kb = [NH₄⁺] [OH⁻] / [NH₃]
To find Kb you need to find the concentration of each species. The equilibrium concentrations are:
[NH₃] = 0.950M - X
[NH₄⁺] = X
[OH⁻] = X
Where X is reaction coordinate.
You can know [OH⁻] and, therefore, X, with pH of the solution, thus:
pH = -log [H⁺] = 11.612
[H⁺] = 2.4434x10⁻¹²
As 1x10⁻¹⁴ = [H⁺] [OH⁻]
1x10⁻¹⁴ / 2.4434x10⁻¹² = [OH⁻]
4.0926x10⁻³ = [OH⁻] = X
Replacing, concentrations of the species are:
[NH₃] = 0.950M - X
[NH₄⁺] = X
[OH⁻] = X
[NH₃] = 0.9459M
[NH₄⁺] = 4.0926x10⁻³M
[OH⁻] = 4.0926x10⁻³M
Replacing in Kb expression:
Kb = [NH₄⁺] [OH⁻] / [NH₃]
Kb = [4.0926x10⁻³M] [4.0926x10⁻³M] / [0.9459M]
The branch of science which deals with the chemical bond is called Chemistry.
The correct answer to the question is [tex]Kb = 1.77*10^{-5[/tex]
Explanation:
When NH₃, is acts as a weak base it forms an equilibrium with water the reaction occurs is:
[tex]NH_3(aq) + H_2O(l) ---><NH_4^+(aq) + OH^-(aq)[/tex]
The formula we gonna use is as follows:-
[tex]Kb = \frac{[NH_4^+] [OH^-]}{[NH_3]}[/tex]
The data is given in the question is as follows:-
Where X stands for reaction coordinate.
After solving the ph of the compound the value is as follows:-
Putting the value in the formula.
[tex]Kb = \frac{[4.0926*10^{-3}M] [4.0926*10^{-3}M]}{[0.9459M]}[/tex]
After solving the equation the value of Kb is [tex]1.77*10^{-5[/tex]
Hence, the correct answer is [tex]1.77*10^{-5[/tex]
For more information, refer to the link:-
https://brainly.com/question/25026730
