What types of substances typically dissolve in water?

Water is often referred to as the "universal solvent" because of its ability to dissolve a wide variety of substances. The reason why polar and ionic substances typically dissolve in water is directly tied to the molecular structure and properties of water itself.

Water molecules are polar, which means they have a partial positive charge on one side (the hydrogen side) and a partial negative charge on the other side (the oxygen side). This polarity allows water molecules to interact with other polar molecules and ions effectively. When ionic compounds, such as salt, are placed in water, for example, the positive part of water molecules attracts the negatively charged ions (anions), while the negative part of the water molecules attracts the positively charged ions (cations). This interaction helps to separate the ions from each other, allowing them to disperse throughout the solution, leading to dissolution.

Similarly, polar substances, which also have regions of partial positive and negative charges, can form hydrogen bonds or dipole-dipole interactions with water molecules, further enhancing their solubility. In contrast, nonpolar substances do not have this charge separation and cannot interact effectively with water, leading to their insolubility.

Ultimately, the capacity of water to dissolve polar and ionic substances is a fundamental