Solubility in presence of complexing agents and pH

37 questions on Solubility in presence of complexing agents and pH from the Ionic Equilibrium II chapter: 7 NEET level, 15 JEE Main, 15 JEE Advanced. Each one opens with its answer and solution.

• The solubility of AgCl in water is increased by adding aqueous ammonia. The main reason is NEET level
• The solubility of which of the following sparingly soluble salts is practically unaffected when the pH of the solution is lowered by adding a strong acid? NEET level
• Saturated aqueous Mg(OH)2 has K_sp = 4.0 x 10^-12 at 298 K. Taking log 2 = 0.301, its pH is NEET level
• For AgCl, K_sp = 1.8 x 10^-10, and for Ag+ + 2NH3 leftharpoons [Ag(NH3)2]+, K_f = 1.6 x 10^7. The equilibrium constant of AgCl(s) + 2NH3 leftharpoons [Ag(NH3)2]... NEET level
• Find the solubility of AgCl in 1.0 M aqueous NH3 (in mol L^-1). K_sp(AgCl) = 1.8 x 10^-10, K_f([Ag(NH3)2]+) = 1.6 x 10^7. Neglect any other complex. JEE Main level
• Find the solubility of CaF2 in a buffer of fixed pH 3.00 (in mol L^-1). K_sp(CaF2) = 3.9 x 10^-11; K_a(HF) = 6.6 x 10^-4. Assume all fluoride is present as F- o... JEE Main level
• A sparingly soluble salt MA (K_sp = 2.0 x 10^-10) is the salt of a weak acid HA with K_a = 1.8 x 10^-5. Its solubility in a buffer of pH 4.00 is (neglect hydrol... JEE Main level
• Find the solubility of Mg(OH)2 in a buffer maintained at pH 9.20 (298 K). K_sp(Mg(OH)2) = 1.2 x 10^-11, K_w = 1.0 x 10^-14, 10^-4.8 = 1.585 x 10^-5. Give the an... JEE Main level
• Find the solubility of AgBr in 0.10 M Na2S2O3 solution, using AgBr(s) + 2S2O3^2- leftharpoons [Ag(S2O3)2]^3- + Br- with K_sp(AgBr) = 5.0 x 10^-13 and K_f([Ag(S2... JEE Main level
• Select the correct statement(s) about the solubility of sparingly soluble salts at constant temperature. JEE Main level
• A sparingly soluble salt MA has K_sp = 1.0 x 10^-10 and HA has K_a = 1.0 x 10^-5. In a buffer of fixed pH the solubility is S = sqrtK_sp(1 + [H+]/K_a) (neglect ... JEE Main level
• Find the solubility of AgCl in a solution containing 0.10 M NaCl and 1.0 M NH3 (assume no volume change and ignore [AgCl2]-). K_sp(AgCl) = 1.8 x 10^-10, K_f([Ag... JEE Advanced level
• Find the solubility of Mg(OH)2 in 0.50 M NH4Cl solution, from Mg(OH)2(s) + 2NH4+ leftharpoons Mg^2+ + 2NH3 + 2H2O. Given K_sp(Mg(OH)2) = 1.2 x 10^-11 and K_b(NH... JEE Advanced level
• Find the solubility of CaC2O4 in a buffer of fixed pH 2.00. K_sp(CaC2O4) = 2.3 x 10^-9; for oxalic acid K_a1 = 5.6 x 10^-2, K_a2 = 5.4 x 10^-5. Total dissolved ... JEE Advanced level
• 50 mL of 0.20 M MgCl2 is mixed with 50 mL of 0.40 M NH3. What minimum mass of solid NH4Cl (molar mass 53.5 g mol^-1) must be dissolved in this mixture (no volum... JEE Advanced level
• A solution is 0.050 M in Cl- and contains 0.020 M total silver, all of it present as [Ag(NH3)2]+ for practical purposes. What minimum total concentration of NH3... JEE Advanced level
• In 1.0 M aqueous NH3 the silver halides dissolve as AgX(s) + 2NH3 leftharpoons [Ag(NH3)2]+ + X-. Use K_f([Ag(NH3)2]+) = 1.6 x 10^7 and K_sp: AgCl 1.8 x 10^-10, ... JEE Advanced level
• A solution contains 0.050 M Mg^2+, 0.10 M NH3 and 0.20 M NH4Cl. K_b(NH3) = 1.8 x 10^-5, K_sp(Mg(OH)2) = 1.2 x 10^-11, K_w = 1.0 x 10^-14. Select the correct sta... JEE Advanced level
• The solubility of silver chloride in water is increased markedly by adding aqueous ammonia. The main reason is NEET level
• The solubility of which of the following sparingly soluble salts is increased most by lowering the pH of the solution? NEET level
• The solubility product of Mg(OH)2 is 4.0x 10^-12 at 298 K. The pH of its saturated aqueous solution is NEET level
• What is the solubility of Mg(OH)2 (K_sp = 1.2x 10^-11) in a buffer of constant pH = 11.00? JEE Main level
• Calculate the solubility of AgCl in 0.10 M aqueous NH3. K_sp(AgCl) = 1.8x 10^-10 and K_f of [Ag(NH3)2]+ = 1.6x 10^7. The complex [Ag(NH3)2]+ is the only silver ... JEE Main level
• Find the solubility of CaF2 (K_sp = 4.0x 10^-11) in a buffer of pH = 3.00. The fluoride released partly forms HF (K_a = 6.6x 10^-4); assume the pH stays constan... JEE Main level
• The ratio of the solubility of Mg(OH)2 in a buffer of pH 9.0 to its solubility in a buffer of pH 11.0 (buffers do not otherwise react with Mg(OH)2) is JEE Main level
• A sparingly soluble salt MX has K_sp = 2.0x 10^-10. The anion X- is the conjugate base of the weak acid HX (K_a = 5.0x 10^-5). Find the solubility of MX in a bu... JEE Main level
• Calculate the solubility of AgBr in 1.00 M aqueous ammonia. K_sp(AgBr) = 5.0x 10^-13; K_f of [Ag(NH3)2]+ = 1.6x 10^7. Treat [Ag(NH3)2]+ as the only dissolved si... JEE Main level
• What minimum total concentration of ammonia (mol per litre of solution) is needed to just dissolve 0.010 mol of AgCl in 1.0 L (no volume change)? K_sp(AgCl) = 1... JEE Main level
• A solution is 0.010 M in Mg^2+ and 0.10 M in NH3 (K_b = 1.8x 10^-5). What is the minimum concentration of NH4Cl (in mol/L, three decimals) that must be added to... JEE Main level
• Zn(OH)2 (K_sp = 3.0x 10^-17) is amphoteric and also forms [Zn(OH)4]^2- (Zn^2+ + 4OH- <=> [Zn(OH)4]^2-, beta_4 = 2.0x 10^15). Its total dissolved zinc is s = [Zn... JEE Advanced level
• Find the solubility of AgCl in a solution that is 0.50 M in NH3 (before dissolving) and also contains 0.10 M NaCl. K_sp = 1.8x 10^-10, K_f([Ag(NH3)2]+) = 1.6x 1... JEE Advanced level
• 100 mL of 0.020 M ZnCl2 is mixed with 100 mL of a solution of hydrochloric acid saturated with H2S, such that after mixing [H2S] = 0.10 M. Given K_sp(ZnS) = 2.0... JEE Advanced level
• Calculate the solubility of CaC2O4 (K_sp = 2.3x 10^-9) in a buffer of pH 3.00. For oxalic acid K_a1 = 5.6x 10^-2 and K_a2 = 5.4x 10^-5; oxalate exists as C2O4^2... JEE Advanced level
• In a hypothetical case, Pb(OH)2 (K_sp = 1.2x 10^-15) dissolves in alkali as Pb(OH)2 + OH- <=> [Pb(OH)3]- because Pb^2+ + 3OH- <=> [Pb(OH)3]- has K_f = 3.8x 10^1... JEE Advanced level
• The following concern AgCl (K_sp = 1.8x 10^-10) and [Ag(NH3)2]+ (K_f = 1.6x 10^7). Take the solubility in 0.10 M NH3 as 4.8x 10^-3 M and in water as 1.3x 10^-5 ... JEE Advanced level
• The solubility of each salt is compared in a buffer of pH 3.0 and in a buffer of pH 7.0. Data: K_a(HF) = 6.6x 10^-4; K_a(HCN) = 6.2x 10^-10; HCl is a strong aci... JEE Advanced level
• Mg(OH)2 dissolves in ammonium chloride by Mg(OH)2 + 2NH4+ <=> Mg^2+ + 2NH3 + 2H2O. Take K_sp(Mg(OH)2) = 1.2x 10^-11 and K_b(NH3) = 1.8x 10^-5. Treat the equilib... JEE Advanced level