Solute and solvent are words that often go together in chemistry. When they are mixed, they make a solution. Learn about how to identify the solute and the solvent, properties of each, and real-world examples of solvents and solutes.
If you don’t know what a solution in chemistry is, it is also highly recommended to review this article on solutions first!
What is a solute?
A solute is a molecule or particle that is distributed in a solvent. There will always be less solute than solvent. That means in a solution the solute is always the minor component. Typically, the solute will be uniformly distributed in the solvent after mixing. Practically, the solute is also usually being added to the solvent. Solutes can be particles, atoms, or molecules.
For example, salts are a common solute. When you add salt to water the salt dissolves and distributes uniformly within the water. There is more water than salt. So then we know that water is the solvent.
A solute can be a solid, liquid, or gas. The solute also does not have to be in the same phase as the solvent it is put into. For example, in soda, the gas bubbles (solute) are dispersed in the liquid solvent.
There is a limit to how much solute can dissolve in a certain solution. The saturation point is when no more solute will dissolve in the solvent.
What is a solvent?
The solvent is the molecule that makes up the majority of the solution. There is always more solvent than any other component present. Typically, the solvent is what everything else is dissolved into.
A solvent is typically thought of as liquid, and that is the most common form. It can also be a solid or gas.
There can be both polar and nonpolar solvents. Generally, a polar solvent will dissolve polar molecules. A non-polar solvent will dissolve non-polar molecules. This is sometimes referred to as “like dissolves like”. Polar solvents tend to include a high electronegativity element such as nitrogen or oxygen. Non-polar solvents are generally composed mostly of carbon and hydrogen.
Solute vs Solvent
The solvent is always the majority component. The solute is the minor component. This is the clearest way to distinguish between solvent and solute. And there can be more than one solute in a given solvent.
For example, thinking about chocolate chip cookie dough ice cream as a macroscopic example, the solvent would be the vanilla ice cream and the cookie dough and the chocolate chips are the solutes. There is more vanilla ice cream than cookie dough. Therefore, the vanilla ice cream must be the solvent. You may also think of it as the cookie dough being distributed within the ice cream. This fact indicates that the cookie dough is the solute. Cookie dough ice cream isn’t actually a solution (because it is heterogeneous, not homogeneous), but it is a good way to remember the parts of a solution.
The Universal Solvent
Water is known as the ‘universal solvent’. Water does not dissolve everything, but it does dissolve many many things. More substances dissolve in water than any other common solvent. And that is where the designation of universal solvent comes from.
Why is water so good at being a solvent? Water is a very polar molecule. Oxygen is highly electronegative, increasing the polarization. With a slight positive charge near the hydrogens and a negative charge near the oxygen. This means it can attract both positively and negatively charged molecules or ions. These factors make water an excellent solvent.
Water as a universal solvent is necessary to keep our earth functioning as we know it. As water travels, it picks up many different solutes along the way—minerals, salts, and nutrients. The water then distributes these as it flows to new areas. If these particles did not dissolve in water, many cycles on the earth would slow or stop completely.
Water also plays an important role in our bodies as a solvent. The kidney removes many chemicals that need to be excreted from the body. Water then dissolves these chemicals (solutes) into it and carries them away. If the body had to have a different solvent for each different group of chemicals, the body would be more complicated than it already is! Water, because it is a universal solvent, can carry away a wide range of chemicals.
It is also a chemistry term! Learn what a solution is, how to identify a solution, and examples of common solutions are below!
Is Water a Solvent or Solute?
Water can be either a solvent or a solute! For example, you could mix water and toluene together. (Toluene is another common chemistry solvent.) If you have 70% water and 30% toluene then water is the solvent. However, if instead, you mix 75% toluene and 25% water, water is now the solute. It all depends on what the majority component is in the solution.
Common Solvent Examples
Here is a list of some common solvents used in chemistry:
- Water
- Oil
- Isopropyl alcohol (IPA)
- Acetone
- Acetic Acid
- Ethanol
- Chloroform
- Toluene
Common Solute Examples
Here are some common solutes in chemistry:
- Sodium chloride (NaCl) and other salts
- Dyes
- Sugar
- Carbon dioxide in sodas
- Cocoa in hot chocolate
Real-World Examples of Solutes in Solvents
Here is a list of some real-world examples of solutes in solvents
- Salt in seawater
- Antifreeze (ethylene glycol in water)
- Sugar in coffee or tea
- Brass (various metals mixed into copper)