Why is water called the universal solvent?

Why is water called the universal solvent?

02

01

It is water's chemical composition and physical attributes that make it such an excellent solvent. Water molecules have a polar arrangement of oxygen and hydrogen atoms—one side (hydrogen) has a positive electrical charge and the other side (oxygen) had a negative charge. This allows the water molecule to become attracted to many other different types of molecules. Water can become so heavily attracted to a different compound, like salt (NaCl), that it can disrupt the attractive forces that hold the sodium and chloride in the salt compound together and, thus, dissolve it.

Water is called the "universal solvent" because it is capable of dissolving more substances than any other liquid. This is important to every living thing on earth. It means that wherever water goes, either through the air, the ground, or through our bodies, it takes along valuable chemicals, minerals, and nutrients.

Our kidneys and water make a great pair

Why salt dissolves in water

Consider how ordinary table salt (NaCl) dissolves in water. Salt is an ionic compound that dissolves into a sodium ion (Na+) and a chlorine ion (Cl–). The water molecules orient so that the negatively-charged oxygen atoms face the positively-charged sodium atoms in salt, while the positively-charged hydrogen atoms face the negatively-charged chlorine atoms. The ionic bond is a strong chemical bond, but the action of all the water molecules is sufficient to pull the sodium and chlorine atoms apart.

Our own kidneys and water's solvent properties make a great pair in keeping us alive and healthy. The kidneys are responsible for filtering out substances that enter our bodies from the foods and drinks we consume. But, the kidneys have got to get rid of these substances after they accumulate them. That is where water helps out; being such a great solvent, water washing through the kidneys dissolves these substances and sends them on the way out of our bodies.

Once separated, the ions evenly distribute and form a chemical solution. This brings up an important point about solvents. Their activity depends on temperature. If you add salt to ice water, very little dissolves. If you add salt to boiling water, much more salt dissolves. Raising the temperature typically increases the effectiveness of a solvent because it increases the kinetic energy of particles. More kinetic energy results in more interaction between particles, so dissolving occurs more quickly.

Water