Water is a universal solvent because it is capable of dissolving a wide variety of substances thanks to its polarized nature, which allows it to interact with charged molecules and ions present in these substances.
Water is a small, simple molecule but quite special. Composed of one oxygen atom and two hydrogen atoms (that's why it's called H₂O), it has a so-called polar structure. Essentially, the oxygen atom attracts electrons more strongly than the hydrogen, so the molecule has a slightly negative area on the oxygen side and a slightly positive area on the hydrogen side. This polarity allows for special bonds, called hydrogen bonds, to form between water molecules themselves. These small bonds, taken individually, are not very strong, but together they make water quite robust, for example, by maintaining a certain cohesion and giving it a surface tension. It is also thanks to these same bonds that water boils at 100°C rather than at a much lower temperature like other similar substances. This fragile and dynamic network of hydrogen bonds, which constantly forms and breaks, makes water particularly interesting from a chemical standpoint and explains its remarkable properties.
When a substance dissolves, its particles disperse uniformly in water, forming a solution. This phenomenon, called dissolution, primarily relies on the interaction between water molecules and the particles of the dissolved substance. Due to their small size and high polarity, water molecules surround the particles of the compound; this process is called solvation. They stick around and effectively separate these particles from each other. As a result, solid or liquid substances become invisible to the eye and form super homogeneous mixtures. It is notably this exceptional ability of water to solvate a wide variety of compounds that earns it the nickname of universal solvent.
Water is a molecule that we call polar, meaning it has a slightly positive end near the hydrogen atoms and a slightly negative end near the oxygen atom. This creates a sort of microscopic magnet. As a result, when an ionic substance (like table salt, NaCl) or polar substance (like sugar) is immersed in water, it is attracted to these opposing poles. The negative parts of the water cling to the positive ions (like sodium, Na⁺), while its positive parts are attracted to the negative ions (like chloride, Cl⁻). Water separates these substances into small pieces, surrounds each ion by forming a sort of shield called a hydration sphere, and voilà, the substance disappears in the water—it is dissolved. That’s why oil, which is non-polar, refuses to mix with water: they simply have little in common and prefer to stay on their respective sides.
Water is somewhat the invisible star of biology. It allows cells to easily transport nutrients and eliminate their waste. Without it, no biochemical reactions are possible. Thanks to its ability to dissolve many substances, it carries vital things like mineral salts, glucose, and dissolved gases. In our blood, it is responsible for circulating oxygen and carbon dioxide. At a chemical level, it also helps maintain molecules in good shape so they can meet and react. Without water, life as we know it would be simply impossible.
Hot water generally dissolves solids better than cold water. That’s why sugar dissolves much more quickly in your hot tea than in iced water!
Ice floats on liquid water because, when it freezes, its molecules arrange themselves in an open crystal structure, making ice less dense than liquid water—an essential phenomenon that allows aquatic life to thrive under frozen lakes!
Every drop of water you drink today is most likely made up of molecules that have been recycled by nature for millions of years, traveling through oceans, clouds, glaciers, and even living organisms.
Despite its nickname as the 'universal solvent', water does not effectively dissolve non-polar substances such as oil, which explains why oil floats on the surface of water instead of mixing.
Sure! Here’s the translation: "Yes, certain substances such as fats or oils are non-polar and do not easily dissolve in water. They are hydrophobic and prefer to dissolve in non-polar solvents like hexane or benzene."
The polarity of water induces an uneven distribution of electric charges within its molecules, creating a negative side (oxygen) and positive sides (hydrogen). This allows water to easily surround the positive or negative ions of a substance, separating them from each other and thus ensuring their dissolution.
Thermal energy promotes the movement of water molecules, which increases the interaction between water molecules and the particles of the substance to be dissolved. Thus, as the temperature rises, dissolution generally becomes more efficient for most solid or liquid substances.
Yes, the dissolving properties of water can sometimes have harmful impacts. For example, water's ability to dissolve pollutants and toxic chemicals often leads to their rapid spread in the environment, potentially affecting aquatic ecosystems and human health.
Water is called the 'universal solvent' due to its exceptional ability to dissolve a wide variety of chemical substances. This property mainly arises from its significant polarity and hydrogen bonding, which facilitate the dissolution of many ionic and polar molecular compounds.
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