What determines whether a compound will dissolve in water?

Answer 1

Water is known as a very polar solvent. That is, the molecules have localized area of concentrated electrical charge. The oxygen atoms are regions of (-) charge and the hydrogen atoms are areas of (+) charge. These areas of localized charge want to interact with neighboring areas of opposite charge. So, oxygen atoms tend to form loose bonds with hydrogen atoms on other nearby water molecules. This lowers the energy of the entire system and therefore promotes stability. For this reason any compound that is able to mimic the tendency of a water molecule to interact with another water molecule will ensure that the compound will indeed enter into association with water (that is, dissolve). The occurrence of groups containing local charge on the solute molecule ensure its ability to dissolve in water. Specifically, polar groups such as OH, NH, CO are associated with the ability to dissolve in water. Certainly the occurrence of net charge (+/-) on a molecule that contains an ionizable group (COOH, NH2, PO4, etc) is a good indicator of water solubility.

Answer 2

water is a polar substance due to the high electronegativity of oxygen, making the hydrogens slightly positive and the oxygens slightly negative. This allows water to form weak bonds with other water molecules or non-water molecules that are also electronegative. Substances that are polar are labeled as "Hydrophillic" (as opposed to hydrophobic) because they bond with water. Hydrophobic substances tend not to bond because the water molecules are much more attracted to eachother than they are to the neutral substance. Ionic compounds will also dissolve because they can be seperated into positive and negative ions that easily form a "hydration shell" of water molecules attracted to it.

Answer 3

The polarity of a compound and its interactions with water molecules determine whether it will dissolve in water. Compounds with polar or ionic bonds tend to dissolve in water, as water molecules can surround and break apart the compound's components. Nonpolar compounds typically do not dissolve in water due to lack of interactions with water molecules.

Answer 4

The polarity or charges of compounds will determine if a compound would dissolve in water, where compounds with opposite charges within their molecules dissolve in water.