Chapter 2 Solutions
“One of the most striking properties of water is its ability to dissolve many substances, forming aqueous solutions. Solutions are very important kinds of matter— important for industry and for life. The ocean is an aqueous solution that contains thousands of components: ions of the metals and nonmetals, complex inorganic ions, many different organic substances. The properties of solutions have been extensively studied, and it has been found that they can be correlated in large part by some simple laws.” — Linus Pauling5.
 - 1954 Nobel Prize winner in Chemistry and 1962 Nobel Peace Prize winner](https://upload.wikimedia.org/wikipedia/commons/3/3d/Linus_Pauling_1962.jpg)
Figure 2.1: Linus Pauling - 1954 Nobel Prize winner in Chemistry and 1962 Nobel Peace Prize winner
Key concepts:
- Solutions consist of solute (the component being dissolved) and solvent (the component that is present in the largest amount)
- The mixtures are homogeneous
- The phase is aqueous (aq) if the solvent is water
- Concentration describes solute/solvent ratios and can be expressed in many ways
- Solution properties differ from pure liquids in predictable ways
- Colligative properties are properties of solutions that depend upon the number of dissolved solute particles
Solutions are created when a substance or substances are dissolved in a liquid. The dissolved substances are called solutes while the liquid doing the dissolving is called the solvent and is present in the largest amount.
Here, the ionic compound, potassium dichromate, is dissolved in water. Notice how the resulting solution changed color from that of the pure liquid and the dissolved substance is homogeneously distributed throughout.
](files/ch11/dissolution.png)
Figure 2.2: Potassium dichromate dissolved in water. Figure from OpenStax
Molecular Equation
\[\mathrm{K_2Cr_2O_7}(s) \longrightarrow \mathrm{K_2Cr_2O_7}(aq)\]
Ionic Equation
\[\mathrm{K_2Cr_2O_7}(s) \longrightarrow \mathrm{2K^+}(aq) + \mathrm{Cr_2O_7^{2-}}(aq)\]