Solutions and Mixtures Quiz

Solutions and Mixtures

• Solution: A homogeneous mixture appearing as one substance but composed of two or more pure substances.
• Solute: The substance being dissolved, the smaller part of the solution.
• Solvent: The substance doing the dissolving, the larger part of the solution.

Examples of Solutions

• Saltwater: Salt (solute) dissolved in water (solvent).
• Hot Chocolate: Hot chocolate powder (solute) dissolved in water/milk (solvent).
• Vinegar: Acetic acid (solute) dissolved in water (solvent).
• Ink: Pigments/dyes (solute) dissolved in water (solvent).
• Brass: Zinc (solute) dissolved in copper (solvent).

Factors Affecting Solubility

• Concentration: The amount of solute compared to the solvent. Higher concentration leads to less solubility because there's a limit to how much solute can dissolve. A concentrated solution has a large amount of solute relative to the solvent, while a diluted solution has less solute.
• Temperature: Higher temperatures generally increase the solubility of most solids in liquids and decrease the solubility of most gases. Warmer solvents have faster-moving particles, leading to more collisions and faster dissolving. Increased temperature also allows for more space in the solvent for the solute.
• Pressure: Higher pressure increases the solubility of gases in liquids. This is seen in carbonated drinks.
• Size: Smaller solute particles dissolve faster because the solvent can interact with a greater surface area. A powder dissolves faster than a solid cube because of a larger exposed surface area.

Types of Solutions

• Unsaturated: The solution can dissolve more solute.
• Saturated: The solution contains the maximum amount of solute that can dissolve at a given temperature.
• Supersaturated: The solution contains more solute than it can normally hold at a given temperature; this is unstable and crystals can form.

Making Rock Candy

• Rock candy is made by creating a supersaturated sugar solution, allowing crystals to form.

Separating Mixtures

• Paper Chromatography: Separates mixtures based on how different components interact with the stationary phase (paper) and mobile phase (liquid solvent). Used to identify and quantify components. Applications include food industry analysis and identifying chemical structures.
• Filtration: Separates insoluble solids from liquids using filter paper to trap the solid. Applications include water treatment and separating solids like stones/particles from fluids.
• Evaporation: Separates a soluble solid from a liquid by boiling away the liquid. Used for recovering salt from saltwater and collecting pure water/removes bacteria.
• Magnetism: Separates mixtures of magnetic and non-magnetic materials using a magnet. Applications include removing metal bits from rocks or sand.
• Distillation: Separates a liquid from a dissolved solid. The liquid is boiled, its vapor is condensed, and the pure liquid is collected. This process removes solutes like salt from solvents like water, used in desalination processes.
• Fractional Distillation: Separates components of a liquid mixture with different boiling points, like separating crude oil into its various products.

Rock Candy Procedure

• A supersaturated sugar solution is heated, cooled, and a sugar crystal is used to help the sugar crystallize to form rock candy crystals.