In everyday life, you can often find that things dissolve in water like dried tea leaves in hot water give flavor and color. The sugar in the tea dissolves and sweeten the tea. But does water dissolve everything? Why is water called a universal solvent? Let’s find out.
Water also functions as a solvent in our body and thus transports vital substances. For aquatic animals, for example, the oxygen dissolved in water is vital. In technology, at home and in nature, water is by far the most potent solvent. Hence, it is called a universal solvent. If you throw a piece of sugar (a solid) into a glass of water, the sugar molecules are distributed in the solvent water. According to the Dalton model, the sugar molecules mix with the water molecules.
This creates a uniform mixture called a solution. If you continuously add sugar to the water, the point quickly comes to the point where the sugar no longer dissolves, and we have a saturated solution. The undissolved solid sugar now remains at the bottom of the vessel.
The mass of a substance that just dissolves in a certain volume of a solvent is called solubility. It depends on the temperature of the solvent. The thermal movement of the solvent particles and the solid particles plays a role in the solution. It leads to the slow mixing of both substances called diffusion.
Solubility depends on temperature and pressure.
The solubility of most solids increases with the increasing temperature of the solvent. The temperature dependence of the solution process is typical for a substance. While the solubility of table salt hardly changes with increasing temperature, that of the Nitric acid increases substantially.
Let’s explain why water is a universal solvent.
Water owes its special properties to its molecular structure. It is a relatively simple structure with one oxygen and two hydrogen atoms, which makes water a universal solvent for solid, liquid, and gaseous substances. The water molecule has a dipole structure(double-pole). The oxygen atom has a negative partial charge, the hydrogen atoms have a positive partial charge. Charged particles such as salts or other polar liquids dissolve very well in water because the unequal charges attract each other.
Our body works through chemical changes that occur at the cellular level. These changes take place in aqueous solutions or solutions in which water is the main solvent. Because water has a polarity (negative and positive charge) and the ability to form hydrogen bonds, water is called a universal solvent. The ability of water to dissolve a variety of molecules is key to these chemical reactions in organisms. Hence the importance of water for life on the planet.
Is water really a universal solvent?
Water has the ability to dissolve a large amount of solutes, more than any other liquid, that is why water is called a universal solvent. It is important to mention that not all substances dissolve well in water, for example, oils. The molecules of the oils have neither positive nor negative charge areas, which is why they are not attracted to water molecules.
Fats and oils that have a large molecular structure or are not charged are repelled by the water. You can observe this if you add oil to water. The oil does not dissolve but floats above the water. Water-soluble substances are referred to as Hydrophilic and water-insoluble substances as Hydrophobic.
Water molecules consist of hydrogen and oxygen atoms. Hydrogen is positively charged, and oxygen is negatively charged. As a result, water molecules can be attracted to and dissolve many different types of molecules. There are other properties of water, such as surface tension, its unique density, and temperature, that allow water to be a universal solvent. There are three possible forms of water, e.g., gas, liquid or solid, a feature that is usually not found in other solvents.
Suggested Read- Why Is Water Essential For Life
The importance of the solution process for living beings
Water is truly a universal solvent, even if some of the substances do not dissolve in it. In living things, water serves as a solvent for nutrients and other vital substances as a means of transport, and aquatic animals breathe the oxygen dissolved in the water. Rivers can heat up due to the cooling water of power plants or factories, which means that the oxygen content of the rivers decreases. To protect the survival of aquatic animals, we need to ensure that wastewater must not warm the rivers above 28 ° C. If toxins from wastewater dissolve in the water, fish may die massively with severe consequences to the environment.