Overview of Water
The only common substance found naturally in all three states of matter, the liquid form of water is the most abundant substance on the Earth's surface. The solid phase of water, ice, is actually less dense than the liquid phase. What are some of the other physical and chemical properties of water that make it so vital for life? The solvent properties of water are essential for life processes as we understand them. Aqueous solution or suspension is the real context of biochemistry with the solubility properties of macromolecules in water being a primary driver of their biochemical behavior. The ability of water to form strong hydrogen bonds is at the heart of its solvency. The surface tension, dielectric properties, and amphoteric nature of water are all unique and necessary for life.
Water on the MCATAlthough you will only see a few direct questions about water on the MCAT, the aqueous solution context is simply the most important field of phenomena for both general chemistry (solutions, acids & bases, and electrochemistry) and biology. Direct questions regarding the properties of water entail things like its phase equilibria. The H - O - H bond angle is a favorite, but for many, many questions on the test, water will figure directly as the medium of the system. Just as the chemical behavior of water plays a crucial role in science, especially a view of general science leading to medicine, water is crucial for the test.