# What concentration of SO32? is in equilibrium with Ag2SO3(s) and 4.20 * 10-3 M Ag ? [SO^2- 3] M=?

## Question:

What concentration of SO32? is in equilibrium with Ag2SO3(s) and 4.20 * 10-3 M Ag ?

M=?

## Molarity

Molar concentration is the quantity of the concentration of a chemical species, in particular of a solute in a solution, in terms of amount of substance per unit volume of solution. It is expressed in moles per liter of solution.

{eq}Ag_2SO_3{(s)} \rightleftharpoons 2Ag^+ + SO_3^{2-} {/eq}

{eq}Ks_p = [Ag^+]^2 [SO^{2-}_3] {/eq}

let moles of {eq}Ag_2SO_3{(s)} {/eq} that dissolve be x, we have 2x moles of {eq}Ag^+ {/eq} and x moles of{eq}SO_3^{2-} {/eq}

Total {eq}Ag^+ {/eq} is

{eq}(2x + 4.20 \times 10^{-3} M Ag ) moles / liter {/eq}

{eq}Ksp = (2x + 4.20 \times 10^{-3})^2 (x) = 1.50 \times 10^{-14} {/eq}

Assuming 2x is less than {eq}4.20 \times 10^{-3} {/eq},then

{eq}(4.20 \times 10^{-3})^2 (x) = 1.50 \times 10^{-14} {/eq}

{eq}x = \frac {1.50 \times 10^{-14}} {(4.20 \times 10^{-3})^2} {/eq}

={eq}8.5 \times 10^{-10} {/eq} moles per liter

{eq}[SO^{2-}_3] = 8.5 \times 10^{-10} M {/eq}