Final answer:
The hydroxide ion concentration [OH-] for a 0.0325 M ammonia solution that is 1.0% ionized is 0.000325 M, and the percent ionization is given to be 1.0%.
Step-by-step explanation:
The question asks to calculate the hydroxide ion concentration ([OH-]) and the percent ionization of a 0.0325-M ammonia solution when it is 1.0% ionized.
To find the hydroxide ion concentration in a 0.0325 M ammonia solution:
- Use the value of Kb for ammonia, which is 1.76 x 10^-5.
- Set up the ionization equilibrium expression for ammonia (NH3 + H2O ⇌ NH4+ + OH-).
- Since ammonia is weakly ionized, the initial concentration of OH- can be assumed to be 0; however, with 1.0% ionization, we can now say 0.0325 M * 1.0% = 0.000325 M of NH3 is ionized into OH-.
- Therefore, [OH-] = 0.000325 M.
- The percent ionization is the ratio of ionized to initial concentration times 100%, which in this case is already given as 1.0%.
In summary, the hydroxide ion concentration is 0.000325 M and the percent ionization is 1.0% for a 0.0325 M solution of ammonia.