Final answer:
The pH of 0.25 M NH₄⁺ (aq) is 0.60.
Step-by-step explanation:
The value for the ionization constant for the ammonium ion (NH₄⁺) is 5.9 x 10⁻¹⁰. To find the pH of 0.25 M NH₄⁺ (aq), we need to use the formula for calculating pH, which is -log[H₃O⁺]. Since NH₄⁺ is an acidic ion, it will release H₃O⁺ ions into solution. Since the concentration of NH₄⁺ is 0.25 M, the concentration of H₃O⁺ ions is also 0.25 M. Therefore, the pH of 0.25 M NH₄⁺ (aq) is -log(0.25) = 0.60.