Question

TA What is the molar solubility of AgCl in 0.50 M NH3? Ksp for AgCl is 1.8x10-10 and K for Ag(NH3)2 + is 1.7x107 ANSWER: 1.3 x 10-5 M 2.0 x 10-2 M 5.5 x 10-2 M 5.8 x 10-2 M

Answer 1

This question is solved as follows:

Sol- Molar solubility of Ag Cl is asked here, when - [N Hz] = 0.50 m. Kslengtos = 118 x 10-60, ktor 7X As we are given in the question that Agll es dissolved in 0.50m NHs. For this situation, the equation can be critten as follows Agce (s) + 2NH3CO [Ag (Nus),]* + c as Agll is a sparingly soluble salt, the ideal egne is written as - Agt + Agdi (3) + 2NHz (l) [fy (why),]* + 4 + 4 for above son equilibrium constant can be written as: [Ag (NH 3 ) ₂ ] + [a ] [Ag] [Ag + ] [ Ag Cl] [NH₃ 7² Tag (NH3)2 ] [ce] [Ag] [Ag + ] [ NH3 / [Agl] Kue k sp 1.8x 10-10 keq = Keg = 1.7 X 10 x 3.06 x 10-3

Now comena deact to the line of is dissolved in NH we calculate Ag (NH3), 7t at any time t, when established arrestion that Age the amount of equilibrie Vs Ag ce (s) + 2NH3 (1) - [Ag (NH3)2 1 taq) + ce-Cag) t= 0 1 0 0.50 (0.50 -2x) solubility TAg (NH3) ₂ [ca Ag cl] [NH ₂² to be constant 306X 10 - solid phase, considered x x (0.50-2x)

2x can be ignored or 3.06 x 10 3 = x - (0.50-22) 3.06 x 10-3 = x² attt 0.504 (0.50) x² = 3.06x0.25 x 10-3 & x² = 0.765 X 10 -3. x = 0.000765 x = 0.02765 mol/dm3 or x = 2.76 x 10-2 mol/dm3 nearly matches with option (6) or second option. Ang