Question

Silver chloride (`AgCI`) is relatively insoluble in water. At 25 C, `1.3 x 10^3` L of water is needed to dissolve 2.5 g of `AgCl`. What mass (in milligrams) of `AgCl` will dissolve in 1.0 L of water?

Answer 1

Approx. `2*mg`

Explanation:

`"Solubility"` `=` `"Moles of solute"/"Volume of solution"`.

For silver chloride we are given that: `2.5*g` wil dissolve in over `1` `m^3` of water.

And thus, `"Solubility"` `=` `(2.5*g)/(143.32*g*mol^-1)xx1/(1.3xx10^3*L)` `=` `1.34xx10^-5*mol*L^-1`.

And thus silver chloride solute in 1L of saturated water `=` `1.34xx10^-5*mol*L^-1xx143.32*g*mol^-1xx1L` `~=` `2*mg`

Typically, you are quoted a `K_"sp"` for these insoluble salts. `K_"sp "AgCl=1.77xx10^-10`. `K_"sp"` values can be shown to depend on the molar solubilities.