Solvent
Definition and meaning of Solvent in chemistry.
A solvent is the substance in a solution that dissolves another substance, called the solute, to form a uniform mixture. It is usually the component present in the largest amount. The solvent typically sets the physical state of the resulting solution.
In more detail
When a solute dissolves in a solvent, its particles spread evenly throughout the solvent. The mixture then looks and behaves like a single substance. Solutions are most often liquids, but solid solutions, like metal alloys, and gas solutions, like air, also exist.
Chemists classify solvents as polar or nonpolar based on how their molecules distribute electric charge. Polar solvents, such as water, have an uneven charge distribution and dissolve other polar substances and ionic compounds well. Nonpolar solvents, such as hexane, have an even charge distribution and dissolve nonpolar substances like oils and fats.
This pattern is summarized by the rule like dissolves like. Water is often called the universal solvent because of its highly polar, bent molecular shape. This shape lets it dissolve an unusually wide range of substances, from table salt to sugar to many gases.
No solvent actually dissolves everything, so the name is a helpful simplification rather than a literal claim. A common misconception is that any two liquids will mix if you stir long enough. Oil and water stay separated no matter how much they are stirred.
Their very different polarities prevent them from forming a uniform mixture. Choosing the right solvent is essential in labs and industry, since it affects reaction rates, extraction efficiency, and product purity.
Key facts
| Field | General Chemistry |
|---|---|
| Universal solvent | Water (H2O) |
| Rule of thumb | Like dissolves like |
| Usual state of matter | Liquid, though solid and gas solutions exist |
| Polar solvent example | Water |
| Nonpolar solvent example | Hexane |
In a cup of instant coffee, hot liquid water acts as the solvent. It dissolves the solid coffee granules. This spreads their flavor and color evenly throughout the cup.
Frequently asked questions
What does 'like dissolves like' mean in chemistry?
It means polar solvents tend to dissolve polar solutes, while nonpolar solvents tend to dissolve nonpolar solutes. Similar polarity between solute and solvent allows the mixture to form.
Why is water called the universal solvent?
Water's polar, bent molecular shape lets it dissolve an unusually wide range of ionic and polar substances. No solvent dissolves everything, but water comes closer than most.
Why don't oil and water mix?
Oil is nonpolar and water is polar, so their molecules are not attracted to each other strongly enough to form a uniform solution, no matter how much they are stirred.