Question

a) Silver chromate, Ag2CrO4 is sparingly soluble in water with a Ksp 112 x 10-12. What is the molar solubility. S, of silver chromate in pure water? Consult Textbook Numerical Answer b) What is the molar solubility in a 130 M solution of K2CrO? Numerical Answer: c) What is the molar solubility in a 130 M solution of AgNO3? Numerical Answer

Answer 1

a) Ag_2 CrO_4 rightwardsdoublearrow 2 Ag^+ + CrO_4^-2 If s are the moles of salt that solubilize, you have solubilized 2s mol of Ag^+ and s mol of chromate. Ksp = [Ag^+]^2 [CrO_4^-2] = (2s)^2 times s = 4s^3 1.12 times 10^-12 = 4s^3 hence s = j squareroot 1.12 times 10^-12/4 s = 6.5 times 10^-5 that is the solubility in mol/2 in pure water b) In a solution of one same ion, you have also the ions of new salt. So here you have a solution of a 1.30 m potassium chromate K_sp = [Ag^+]^2 [CrO_4^-2] = (2s)^2 times (s + 1.30) Since, s is small compared to 1.30, we can write Ksp = (2s)^2 times (1.30) 1.12 times 10^-12 = 5.2 s^2 s = squareroot 1.12 times 10^-12/5.2 s = 4.6 times 10^-7 mol/L That is about 100 times less soluble of the solution in pure water. \r\n c) In a solution of silver nitrate, 1.30m you have