Why water is good solvent for ionic substances?
Water is a very polar molecule and has very strong dipolar charges. Being dipolar, water is attracted to other dipolar substances and ionic substances. Those ionic substances with weak enough bonds are so strongly attracted to the dipoles of water, water is able to bond to the ions and “dissolve” them from their ionic solids. On the other hand, molecular compounds have no real dipole forces, and are held together as solids only by London dispersion forces. Since since the dipoles in water cannot interact with the non-charged molecules, those molecules do not “dissolve in water”. However, those molecular substances will dissolve in other molecular substances, because the London forces are not specific for the molecules and freely exchange between those molecules. The general rule for solubility is “like dissolves like.” This means that dipolar compounds will dissolve other dipolar compounds (and some ionic compounds) and molecular compounds will dissolve other molecular compounds, but d
why water is good solvent for ionic substances? Ionic substances are composed of positive and negative ions. For a solvent to dissolve an ionic substance, the following 4 conditions must be met!! 1) To dissolve an ionic compound, a solvent must separate the positive ion from the negative ion. 2) To separate the positive ion from the negative ion, the solvent molecule must attract the positive ion and the negative ion. 3) To attract a positive ion, the molecule of the solvent must have a negative end. 4) To attract a negative ion, the molecule of the solvent must have a positive end. WATER IS A POLAR MOLECULE!! A water molecule has 2 hydrogen atoms bonded to 1 oxygen atom. The electronegativity of the oxygen atom = 3.5. The electronegativity of the hydrogen atom = 2.1. This means the oxygen end of the water molecule has a partial negative charge and the hydrogen end has a partial positive charge. Conditions 1 – 4 are met!! Do a Google search for “salt dissolving in water”, and choose Im
