patino_chm2046_chapter16

010 by 1016 the effect of ph on solubility for

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 x 10-18 = [Hg22+] [Cl-]2 Solution [Cl-] that can exist when [Hg22+] = 0.010 M, [Cl-]2 = Ksp / [Hg22+] [Cl− ] = K sp 0.010 = 1.1 x 10-8 M If this conc. of Cl- is just exceeded, Hg2Cl2 begins to precipitate! begins Precipitating an Insoluble Salt Precipitating Hg2Cl2(s) ⇄ Hg22+(aq) + 2 Cl-(aq) (s) Ksp = 1.1 x 10-18 (Now raise [Cl-]) If we continue adding Cl− until [Cl-] = 1.0 M, What is the value of [Hg22+] at this at point? point? Solution [Hg22+] = Ksp / [Cl-]2 [Cl sp = Ksp / (1.0)2 = 1.1 x 10-18 M The concentration of Hg22+ has been reduced (from 0.010) by 1016 ! The Effect of pH on Solubility • for insoluble ionic hydroxides, the higher the pH, the lower the solubility of the ionic hydroxide – low pH, the higher the solubility (H+ reacts with OH-) – higher pH = increased [OH−] = lowering solubility High [OH−] high pH left M(OH)n(s) ⇄ Mn+(aq) + nOH−(aq) High [H+] low pH right • for insoluble ionic compounds that contain anions of weak acids (HA), the lower the pH (higher [H3O+], lower [A−]), the higher the solubility M2(CO3)n(s) ⇄ 2 Mn+(aq) + nCO32−(aq) H3O+(aq) + CO32− (aq)⇄ HCO3− (aq) + H2O(l) high K65 Barium Sulfate Barium Ksp = 1.1 x 10-10 (a) BaSO4 is a common mineral, appearing as a white powder or colorless crystals. (b) BaSO4 is opaque to x-rays. Drinking a BaSO4 cocktail enables a physician to exam the intestines. The Common Ion Effect Calculate the solubility of BaSO4 in (a) pure Calculate water and (b) in 0.010 M Ba(NO3)2. water Ksp for BaSO4 = 1.1 x 10-10 1.1 BaSO4(s) ⇄ Ba2+(aq) + SO42-(aq) (s) Solution Solubility in pure water = [Ba2+] = [SO42-] = x Ksp = [Ba2+] [SO42-] = x2 x = (Ksp)1/2 = 1.1 x 10-5 M Solubility in pure water = 1.1 x 10-5 mol/L The Common Ion Effect Calculate the solubility of BaSO4 in (a) pure water and (b) in 0.010 M Ba(NO3)2. (b) Ksp for BaSO4 = 1.1 x 10-10 1.1 BaSO4(s) ⇄ Ba2+(aq) + SO42-(aq) (s) add some Ba2+ Solution Solution Solubility in pure water = 1.1 x 10-5 mol/L. Now add BaSO4 to water alread...
View Full Document

This note was uploaded on 11/07/2011 for the course CHM 2045 taught by Professor Geiger during the Fall '08 term at University of Central Florida.

Ask a homework question - tutors are online