Answer to Question #170674 in General Chemistry for Hyeri

Question

Calculate the hydroxide concentrationof a solution that is 0.1 F with NH3 and 0.20 F in respect to (NH4)2SO4.

Answer 1

NH3 + H2O ==> NH4^+ + OH^-

and

(NH4)2SO4 ==> 2NH4^+ + SO4^2-

If [(NH4)2SO4] = 0.20 then [(NH4)^+] = 0.10

Use Kb = (NH4^+)(OH^-)/(NH3).

You know Kb, (NH4)^+ and (NH3). Solve for OH^-

OH-= Kb × NH3 /( NH₄⁺)

= 1.8×10^-5× 0.1 / 0.1

= 1.8×10^-5