Water: The Universal Solvent

     Water is a molecule different from every other molecule out there. The liquid not only can exist in all three states of matter, but is also known as the “universal solvent” because of its amazing ability to dissolve more solutes than any other liquid due to its unique chemical composition.

     Water, or H2O, is made of two hydrogen atoms and one oxygen atom. In water, hydrogen has a partial positive charge and oxygen has a partial negative charge. When these atoms combine, not only is an ionic bond created due to the electrons shared between the atoms, but a polar molecule is as well. In addition, its shape becomes bent, showing the unequal distribution of charge where oxygen has a greater electronegativity, thus attracting more electrons, accounting for it’s partial negative charge.

     Due to its polarity, a water molecule is easily attracted to many other polar molecules and ions. It forms electrostatic interactions with these molecules and ions, interacting like magnets. The partially positive hydrogen attracts the negative ion, and the partially negative oxygen attracts the positive ion. It’s these facts combined that make water such a fantastic solvent.

     For example, when water interacts with salt, it’s able to break apart the attractive forces between the sodium and chloride molecules and dissolve the entire molecule. Digging deeper, if salt is added to water and stirred, a dissociation process occurs where the salt molecule will break into Na⁺ and Cl⁻ ions. Hydration shells are then formed around the ions by water molecules, where Na⁺ is surrounded by the partial negative charges of oxygen and Cl⁻ is surrounded by the partial positive charges of hydrogen. This process continues until all of the ions have been surrounded by the hydration shells and dissolved into the solution.

     The human body also uses water’s solvent properties for many functions, one of which is waste management. After the kidneys filter out substances from the meals we consume, they must have a way in which to flush these substances from our bodies. Water acts as a solvent, dissolving these substances and flushing them from our system.  

     Several chemical reactions that occur in plants, animals, and the overall earth take place in a watery environment inside of cells. Without water’s amazing solvent properties, these reactions wouldn’t be able to take place, which would be bad news for us. The fact that these environments depend on water to dissolve a variety of different substances is just another reason why water is, and must continue be, the “universal solvent”.

     To learn more about how water is the “universal solvent”, visit https://www.e-education.psu.edu/earth540/content/c3_p4.html  


posted in Environment & Sustainability