Solutions play a very important role in many biological, laboratory, and industrial applications of chemistry. Of particular importance are solutions involving substances dissolved in water, or aqueous solutions. Solutions represent equilibrium systems, and the lessons learned in our last unit will be of particular importance again. Quantitative measurements of solutions are another key component of this unit. Solutions can involve all physical states - gases dissolved in gases (the air around us), solids dissolved in solids (metal alloys), liquids dissolved in solids (amalgams - liquid mercury dissolved in another metal such as silver, tin or copper). In this unit we will almost exclusively be concerned with aqueous solutions - substances dissolved in water.
- 9.1: Solutions - Homogeneous Mixtures
- There are two types of mixtures: mixtures in which the substances are evenly mixed together (called a solution) and a mixture in which the substances are not evenly mixed (called a heterogeneous mixture). A solution is an even (or homogeneous) mixture of substances. A point should be made here that when a solution is said to have uniform properties throughout, the definition is referring to properties at the particle level.
- 9.2: Solutions of Solids Dissolved in Water- How to Make Rock Candy
- solutions can be formed in a variety of combinations using solids, liquids, and gases. We also know that solutions have constant composition and we can also vary this composition up to a point to maintain the homogeneous nature of the solution. The reasons why solutions will form will be explored in this section, along with a discussion of why water is used most frequently to dissolve substances of various types.