Determine the ph of a 0.62 m nh4no3 solution at 25°c. The kb for nh3 is 1.76 * 10-5.

ph = 4.73

Explanation:

Determine the pH of a 0.62 M NH4NO3 solution at 25C

The Kb for NH3 is 1.76 x 10^-5

NH4 + is the conjugate acid of the base NH3

Ka for NH4 + = K water / K NH3 conjugate base

Ka = 1 * 10⁻¹⁴ / 1.76 10⁻⁵

= 5.68 * 10⁻¹⁰

which is he Ka for

NH4 + H2O - -> NH4OH + H⁺

Ka = [NH4OH] [H+] / [NH4) + ]

5.68 * 10⁻¹⁰ = [X] [X] / [0.62]

X² = 3.52 * 10⁻¹⁰

X = [H+] = 1.88 * 10⁻⁵

p of that H + = 4.73

ph = 4.73