using Kb, for NH3 (from Appendix E), calculate Ka for the NH4+ ion.
Kb for NH3 is 1.81 x 10^-5
Ka for NH4+ is Kw / Kb = 10^-14 / 1.81 x 10^-5 = 5.52 x 10^-10
Looks good to me.
To calculate the Ka for the NH4+ ion using the Kb for NH3, we can use the equation Ka = Kw / Kb, where Kw is the ion product constant for water.
The Kb for NH3 given in Appendix E is 1.81 x 10^-5.
The ion product constant for water, Kw, is 1.0 x 10^-14 at 25°C.
Plugging these values into the equation, we have:
Ka = Kw / Kb = (1.0 x 10^-14) / (1.81 x 10^-5)
To simplify this calculation, divide the numerator by the denominator:
Ka = 1.0 x 10^-14 / 1.81 x 10^-5 = 5.52 x 10^-10
Hence, the Ka value for the NH4+ ion is 5.52 x 10^-10.