> See also: > - [[Buffer Solutions]] > - [[Intermolecular Forces]] > - [[Solubility vs Dissociation]] # Solutions & Concentrations A **solution** is a *homogenous mixture* composed of one or more **solutes** dissolved in a **solvent**. | Term | Definition | | --- | --- | | **Solute** | The component with the *lower concentration* (Ex: Sugar, Salt, DNA, Proteins) | | **Solvent** | The component with the *higher concentration*. | A *homogenous* mixture is *uniform in composition* and properties throughout the substance (Ex: Milk) while a *heterogeneous* mixture have *visually distinguishable components* (Ex: Soil) Water is the most common solvent; a solution where water is the solvent is known as an *aqueous solution (aq)*. - A solution is *anhydrous* if it contains no water. Substances can [[Solubility vs Dissociation|dissolve and/or dissociate]] when they are introduced to a solution. ## Concentrations > See also: > - [Expressing Concentrations](https://www.chem.purdue.edu/gchelp/solutions/character2.html) The relative amount of a solute dissolved in a given amount of solution is known as the solute’s **concentration**. ### Molarity **Molarity** is the number of moles in a solute compared to the liters $ M = \frac{mol\text{ solute}}{L\text{ solution}}$ Make sure to convert $mL$ to $L$ whenever necessary; these specific units must be used for the ratio to truly be the molarity. ### Molality **Molality** is a measure of the amount of moles of a solute within a solution that would be present within 1 kg of solvent. $m = \frac{mol}{kg}$ See ### Molarity vs Molality | Trait | Molarity (M) | Molality (m) | | --- | --- | --- | | Measure of | Concentration | Concentration | | Definition | The moles of a solute per liters of a *solution*. | The moles of a solute per kilograms of a *solvent*. | | Units | M | m | | Ratio of moles to | Volume (*in liters*) | Mass (*in kilograms*) |