1. Solutions Physical science 2.1.2 1

2. Solutions: Solute and Solvent Solutions are homogeneous mixtures of two or more substances consist of a solvent and one or more solutes 2

3. Solutions A solution is a homogeneous mixture of 2 or more substances in a single phase. A solution is a homogeneous mixture of 2 or more substances in a single phase. One constituent is usually regarded as the SOLVENT and the others as SOLUTES. One constituent is usually regarded as the SOLVENT and the others as SOLUTES. 3

4. Nature of Solutes in Solutions Solutes spread evenly throughout the solution cannot be separated by filtration can be separated by evaporation are not visible but can give a color to the solution 4

5. Examples of Solutions The solute and solvent in a solution can be a solid, liquid, and/or a gas. 5

6. SOLUTE – the part of a solution that is being dissolved (usually the lesser amount) SOLVENT – the part of a solution that dissolves the solute (usually the greater amount) Solute + Solvent = Solution 6 SoluteSolventExample solid Metal alloys solidliquidSalt water gassolidMoth balls liquid Alcohol in water gasliquidsoda gas air

7. Types of solutions Solutions can be classified as saturated or unsaturated. A saturated solution contains the maximum quantity of solute that dissolves at that temperature. An unsaturated solution contains less than the maximum amount of solute that can dissolve at a particular temperature 7

8. Supersaturated SUPERSATURATED SOLUTIONS contain more solute than is possible to be dissolved Supersaturated solutions are unstable. The supersaturation is only temporary, and usually accomplished in one of two ways: 1. Warm the solvent so that it will dissolve more, then cool the solution 2. Evaporate some of the solvent carefully so that the solute does not solidify and come out of solution. 8

9. Dilute and concentrated A dilute solution is a solution in which there is a small amount of solute (the thing that gets dissolved) compared to the total amount of possible solute that can be dissolved in the solvent (the thing that does the dissolving). A concentrated solution is when there is a lot or all solute that can possibly fit in the solvent. 9

10. Water is the most common solvent is a polar molecule forms hydrogen bonds between the hydrogen atom in one molecule and the oxygen atom in a different water molecule 10