Solubility in Water

[Julia Lindner 1I]

Can someone summarize how solubility in water is related to the size, electric dipole moments, and ionic/covalent character of molecules? Are there any other factors that affect solubility? Why are silver halides (AgF, AgCl, AgBr, and AgI) less soluble specifically?

[AustinGrove3B]

In general, molecules with bonds that have higher covalent character are LESS soluble in water. Molecules with bonds with low covalent character / high ionic character are MORE soluble in water. A good way to remember it is that salt, NaCl, is an ionic compound and is extremely easy to dissolve in water.

As explained in class, molecules that can separate into ions are easily dissolvable because the ions will interact with the partial - and + charges on the O and H in the H₂O molecule. Covalent compounds don't separate into ions like that.

As for predicting this, bonds with atoms with larger electronegativity differences will be more ionic in character and easier to dissolve in water.

[BenJohnson1H]

Would it also be correct to say that the more polar a molecule is, the more soluble it is?

[905109118]

Would it also be correct to say that the more polar a molecule is, the more soluble it is?

Yes because polar molecules do dissolve in water as they form hydrogen bonds.

[Alan Chang]

Polar molecules are more soluble in polar solvents and non polar molecules are more soluble in non polar solvents. In this case, water is polar, so polar compounds are more soluble in water.

[Hailey Boehm 2H]

For the last part of your question, AgF is the only silver halide that is soluble in water. This is because F is the most electronegative element, and the electronegativity difference between Ag and F is the highest of the listed silver halides, and high enough for the halide to have ionic character. This means it can dissolve in a polar substance such as water. The other silver halides are nonpolar because the electronegativity differences between Ag and the other group 17 elements are not great enough. Therefore, these nonpolar halides cannot dissolve in a polar substance like water.