(POS) Properties of Solutions Module Overview

Properties of Solutions Module Overview

Who doesn't love a cold glass of lemonade in the summer? Did you know this mixture is a solution? In this module, you will learn the parts that make up a solution. In lemonade, water is the solvent and sugar & lemon juice are the solutes. In addition, you will learn how you can speed up the process of making your solution, whether you prefer to drink a concentrated or diluted solution, what happens when you add too much solute to a solution, and whether the solution is an acid or a base. Does all of this talk about solutions make you thirsty? Go ahead and grab your favorite solution (Kool-Aid, sweet tea, etc) to sip on while you begin this module.

Essential Questions

• What is solubility?
• What are factors that affect solubility?
• What are the properties of acids and bases?
• How can you determine if a substance is an acid, base, or neutral?

Key Terms

1. Mixture - a combination of two or more pure substances physically combined which allows the original substances to retain their chemical properties.
2. Homogenous mixture - a mixture that has uniform composition and properties throughout.
3. Heterogeneous mixture - a mixture that does not blend smoothly throughout and the individual substances that compose the mixture can be detected.
4. Colloid - a homogeneous mixture with medium-sized particles. The particles are large enough to be seen and make things appear cloudy but not large enough to settle or be filtered out of the mixture.
5. Tyndall Effect - a method used to determine if a substance is a colloid by scattering light through the substance.
6. Suspension - a heterogeneous mixture with large particles. The particles are large enough to be seen and also settle or can be filtered out of the mixture.
7. Solution - a homogeneous mixture in which the minor component (the solute) is uniformly distributed within the major component (the solvent).
8. Solute - a substance being dissolved, usually the component of a solution present in the lesser amount.
9. Solvent - a substance doing the dissolving, usually the component of a solution present in the larger amount.
10. Solubility - the ability of a substance to dissolve in a solvent.
11. Saturated - a solution in which the maximum amount of solute has been dissolved in a solvent.
12. Unsaturated - a solution in which more solute can be added and dissolved. It is below the maximum amount of solute.
13. Supersaturated - a solution that contains more of the dissolved solute than could be dissolved by the solvent under normal circumstances. Increasing temperature or pressure can increase the maximum possible saturation.
14. Conductivity - the measure of a solution's ability to conduct electricity.
15. Aqueous solution - a solution in which the solvent is water.
16. Strong electrolytes - a solute that completely, or almost completely, ionizes or dissociates in a solution. These ions are good conductors of electric current in the solution.
17. Weak electrolytes - a solute that only partially ionizes or dissociates in a solutions resulting in low conductivity.
18. Nonelectrolytes - solutions made from covalent compounds have zero conductivity since they dissolve as molecules, not ions. They cannot carry electrical charges.
19. Concentration - describes how much solute has been dissolved in solution and is expressed in some kind of ratio.
20. Concentrated - a solution that contains a large amount of solute relative to the amount that could dissolve.
21. Diluted - a solution that contains a small amount of solute relative to the solvent.
22. Solubility curve - a graph showing how the amount of dissolved solute changes with temperature.
23. Acid - a substance that vigorously reacts with most metals to produce hydrogen, readily conducts electricity, turns litmus red, and has a pH less than 7; typically corrosive or sour-tasting.
24. Base - a substance that does not react with most metals, readily conducts electricity, turns litmus blue, and has a pH greater than 7; typically feels slippery and is bitter-tasting.
25. pH Scale - a measure of the acidity or basicity of a solution. The lower the pH of a solution, the more acidic it is. The higher the pH, the more basic it is.
26. Indicator - any of various substances, such as litmus or phenolphthalein, that indicate if a substance is an acid or base by means of a color change.

[CC BY 4.0] UNLESS OTHERWISE NOTED | IMAGES: LICENSED AND USED ACCORDING TO TERMS OF SUBSCRIPTION