INO-20

Common-ion solubility

[A+] = Ksp / [B−] for AB. Extra B− suppresses dissolved A+.

Reading speed

SolubilityCommon-ion effect

Governing equation

[A^+]=K_{sp}/[B^-]

where

K_{sp}: Ksp (—)
[B^-]: Common-ion concentration (mol/L)
[A^+]: Dissolved cation (mol/L)

Lecture brief

Historical brief

Pauling and Allred–Rochow electronegativity, Kapustinskii lattice energy, CFSE and Goldschmidt radii organise the periodic solid. The sheets predict bond character and crystal packing. This sheet (INO-20 — Common-ion solubility) is the form associated with Common-ion effect. Working symbols: $K_{sp}$ , $[B^-]$ $\rightarrow$ $[A^+]$ . Le Chatelier on the dissolution equilibrium. Valid when [B−] ≫ s.

Purpose

Purpose: compute

[A^+]

from

K_{sp}

[B^-]

in Inorganic chemistry via

[A^+]=K_{sp}/[B^-]

[A+] = Ksp / [B−] for AB. Extra B− suppresses dissolved A+. Use it when a real inorganic chemistry question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

K_{sp} = 1.800e-10\,\mathrm{—}

[B^-] = 0.100\,\mathrm{mol/L}

, the governing relation

[A^+]=K_{sp}/[B^-]

yields

[A^+] = 1.800e-9\,\mathrm{mol/L}

. AB salt plus a strong B− source, neglect activity. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Ksp K_{sp}1.8e-10 —Common-ion concentration [B^-]0.1 mol/L

Outputs

Dissolved cation [A^+]0.000000 mol/L

Reading speed

Watch on YouTube

Free library

Full library

Free PDF / open book

YouTube channels

00:0 / 00:08

Narration of this film

AB salt plus a strong B− source, neglect activity.

Le Chatelier on the dissolution equilibrium. Valid when [B−] ≫ s.

Reading speed

Watch on YouTube