Solutions, Types of Solutions, Properties of Solutions
- 1. Solutions
- 2. Solution: Definition, Components, and Dissolution Process Solutions are mixtures generally referred to as homogenous mixtures. - As you can recall there are 2 two types of mixtures: a. Homogenous – uniform in composition all throughout b. Heterogenous – each component can be easily distinguished Focusing on solutions, the components are classified into Solute – substance that is dissolved Solvent - substance that does the dissolving
- 3. Solution: Solute and Solvent
- 4. How Solutions are formed The process of dissolving a solute in a solvent is called dissolution. In simplicity, dissolution by way of solute-solvent interaction can be described as the process of solute-solvent interaction Their interaction allow them to form solutions Solute molecules interaction become weaker, allowing it to be surrounded by solvent molecules
- 5. How Solutions are Formed
- 6. Types of Solution Solutions you encounter everyday can be of several Types shown in the table below
- 7. More on Solutions: Solubility and Types of Solution based on Solute Present Solubility refers to the amount of solute that may be dissolved in a specific amount of solvent at a given temperature There are three classifications for solutions based on the amount of solute present: 1. Saturated Solution – has the maximum amount of solute dissolved in a given solvent 2. Unsaturated Solution – solution that contains less amount of the solute that may be dissolved in a given solvent 3. Supersaturated Solution - a solution that holds more dissolved solute than it normally can at a given temperature and pressure
- 8. Saturated, Unsaturated, and Supersaturated Solution
- 9. Concentration Units Saturated, Unsaturated, and Supersaturated are all Qualitative ways to describe solutes in a solution To describe Quantitatively, we use concentration Units. Concentration Units – provide specific amount of solute in mass, volume, and moles that is present in a given volume. We will be considering three concentration units that deal with: a. % by mass b. % by volume c. % by mass-volume
- 10. Percentage By Mass The amount of solute (in mass) present in a solution can be given by the following equation:
- 11. Percentage by Volume The percentage/concentration of the solute in a solution, given it’s volume is calculated as:
- 12. Percentage by Mass-Volume Concentration of some commercial products are given by percent by mass-volume. % mass-volume
- 13. Solutions at home: making a juice and dilution Based on the amount of solute present, solutions may be identified as either Concentrated or Diluted Solutions. Concentrated – meaning they have more solute dissolved, and Diluted – meaning less solute dissolved with a given solvent Ever tasted your juice as too sweet? Adding more water makes your juice diluted and more to your liking. Sometimes you reduce the amount of concentrate
- 14. Factors Affecting Solubility A. Nature of Solute and Solvent – this factor can be best understood with a proper background in chemical bonding, polarity, and intermolecular force of attraction. “like dissolves like” If the solute has similar to that of the solvent, it will be soluble Example: Water dissolves salt, sugar, and ethanol, but unable To dissolve iodine crystals and naphthalene. Does not mix with oil
- 16. Factors Affecting Solubility B. Pressure – the effect of pressure on solubility is easily understandable with gas solutes. In a closed system where gas molecules are Present in and out of the solution, an equilibrium (under normal conditions) is established Molecules entering in and out of the solution Is the same; but with an increase in pressure More gas molecules enter the solution -- leading to more solubility
- 17. Factors Affecting Solubility C. Temperature - When temperature is increased, molecules move at a faster rate – gaining kinetic energy. - Solubility of solids/liquids with temperature: - This makes the interaction between the solute molecules weaker, allowing faster dissolution of solute in the solvent. (NOTE: not all solutes dissolve quicker under higher temperature) - Solubility of gases with temperature: - When it comes to solubility of gases, the inverse happens. As temperature increases, the solubility of the gas decreases.
- 18. Factors Affecting Solubility D. Surface Area – large particles of the solute provides less surface area for the solvent molecules to interact with – leading to less solubility The finer or smaller the solute particles, the better the interaction with the solvent – leading to better solubility
- 19. Colligative Properties of a Solution
- 20. Freezing Point Depression Is the lowering of the freezing point of a solvent upon addition of a solute When you add more solute to a solution, the lower it’s freezing point gets
- 21. Boiling point elevation The boiling point of a pure solvent become higher with the addition of a solute The more solute, the higher it’s boiling point
- 22. Vapor pressure lowering Vapor pressure – is defined as the pressure exerted by the vapor above the liquid (or solid) in a closed system. In the presence of a solute, the vapor pressure decreases because the solute prevents the solvent from escaping as a gas.