# With respect to a given solvent what do we mean by solubility?

Jun 12, 2017

Simply that the solid or the liquid is $\text{soluble}$ in the liquid........

#### Explanation:

And assessment of solubility is an experimental phenomenon, and we can advance reasons to attempt to explain the observed solubility. Water is an exceptionally powerful solvent inasmuch as it can solvate many cations and anions..........

$N a C l \left(s\right) \stackrel{{H}_{2} O}{\rightarrow} N a C l \left(a q\right)$

And we write $N a C l \left(a q\right)$ to signify that ionization of the salt has occurred in solution to give solvated aqua ions, i.e. of the sort ${\left[N a {\left(O {H}_{2}\right)}_{6}\right]}^{+}$ or ${\left[C l {\left({H}_{2} O\right)}_{4 - 6}\right]}^{-}$. And in fact most substances have SOME solubility in water.

In hexanes, water has minimal solubility, because the apolar hexanes molecule cannot solvate the dipolar water molecule. On the other hand ethanol, which in infinitely miscible in water, is also SOLUBLE in hexanes. On the other, other hand, methanol, which is infinitely miscible in both water and ethanol, is INSOLUBLE in hexanes. Can you account for these phenomena?

In aqueous solution, general rules of ionic solubility are:

$\text{All the salts of the alkali metals and ammonium are soluble.}$

$\text{All nitrates, and perchlorates are soluble.}$

$\text{All halides are soluble EXCEPT for}$  AgX, Hg_2X_2, PbX_2".

$\text{All sulfates are soluble EXCEPT for}$ $P b S {O}_{4} , B a S {O}_{4} , H g S {O}_{4}$.

$\text{All carbonates and hydroxides are insoluble.}$

$\text{All sulfides are insoluble.}$

The given rules follow a hierarchy. Alkali metal and ammonium salts tend to be soluble in all circumstances. The one exception to this rule is ${K}^{+} B P {h}_{4}$ and $N {H}_{4}^{+} B P {h}_{4}$, both of which are as soluble as bricks. Na^(+)""^(-)BPh_4 is sold as \text{kalignost}, literally $\text{potassium recognizer...}$