For a solution that is 0.168M NH3 and 0.106M NH4Cl calculate the following.

[OH-]
[NH4+]
[Cl-]
[H30+]

pH can be calculated from the Henderson-Hasselbalch equaion.

pOH from pH + pOH = pKw = 14

OH^- from pOH = -log(OH^-)
H3O^+ from pH = -log(H3O^+)
(Cl^-) = NH4Cl
Post your work if you get stuck.

Using the Henderson-Hasselbalch equation, should i write this:

pH= -log ka + log(0.168/0.106)
PH= -log(5.6*10^-10) + log(0.168/0.106)
PH=9.45

@DrBob222 .......Thanks. It worked.

Yes, and 9.45 is correct if Ka is correct. I didn't check that.

To calculate the concentrations of [OH-], [NH4+], [Cl-], and [H3O+], we can use the concept of dissociation of weak acids and bases.

1. To find [OH-], we need to consider the dissociation of water:
H2O ⇌ H+ + OH-
Since water is in equilibrium with H+ and OH-, in pure water at 25°C, [H+] = [OH-] = 1 x 10^-7 M (neutral solution).

However, in this case, we have a solution of NH3 and NH4Cl, which are weak base and weak acid, respectively. The NH4Cl will act as a source of H+ ions, consuming some of the OH- ions and increasing the [H+]. Thus, we need to find the concentration of H+ ions first.

2. To calculate [H3O+], we consider the ionization of NH4Cl:
NH4Cl ⇌ NH4+ + Cl-
This equation shows that NH4Cl dissociates to produce the NH4+ and Cl- ions. Since NH4+ is a weak acid, it can donate a proton (H+) to the solution, increasing the concentration of [H+].

To find the [H+] concentration (or [H3O+]), we can use the equation for the ionization constant of NH4+:
Ka = [NH4+][H3O+]/[NH3]

The value for Ka for NH4+ is known (1.8 x 10^-5), and we have the concentrations of NH4+ (0.106M) and NH3 (0.168M). Using these values, we can solve for [H3O+].

3. Once we have [H3O+], we can find [OH-] using the equation:
Kw = [H3O+][OH-]
The value of Kw, the ionization constant of water, is known (1.0 x 10^-14). Now, we know [H3O+] and can calculate [OH-].

4. To find [NH4+], we use the equation for ionization of NH4+:
[NH4+] = [NH3] - [OH-]
Substitute the known values of [NH3] and [OH-] to calculate [NH4+].

5. Finally, to find [Cl-], we can calculate it from charge balance:
[Cl-] = [NH4Cl] - [NH4+]
Substitute the known concentration of NH4Cl and [NH4+] to find [Cl-].

Please provide the specific concentrations of NH3 and NH4Cl to proceed with the calculations.