Mixtures and separation

• What is the definition of a mixture?


  Mixtures are combinations of two or more substances that are not chemically bonded.
• How can mixtures be separated?


  Mixtures can be separated by physical methods.
• What happens to the properties of substances in a mixture?


  The original properties of substances in a mixture are retained.
• What are the two types of mixtures?


  Homogeneous and heterogeneous mixtures.
• What are the key characteristics of mixtures?


  • No fixed chemical composition
  • Components can be separated physically
  • Original properties of substances are retained
  • Can be homogeneous or heterogeneous
• What are the methods used for physical separation of mixtures?

  • Filtration
  • Distillation
  • Magnetism
  • Evaporation
• Which method would you use to separate a mixture of sand and iron filings?


  Magnetism would be the best method to separate sand and iron filings.
• Why is magnetism effective for separating iron filings from sand?


  Iron is magnetic and will be attracted to a magnet, while sand is not.
• Compare the characteristics of pure substances and mixtures.

  **Pure Substances**:

  • Fixed composition
  • Cannot be separated by physical methods
  • Single type of particle

  
  

  **Mixtures**:

  • Variable composition
  • Can be separated by physical methods
  • Multiple types of particles
• What happens to the components of a mixture during separation?


  Components can be separated physically without a chemical reaction.
• What remains unchanged during the separation of a mixture?


  The original properties of the components remain unchanged.
• What is the basic principle of filtration?

  Filtration uses a porous material to separate solid particles from a liquid or gas.
• What type of material is typically used in filtration?

  Porous material like filter paper.
• What determines whether a particle will be trapped by the filter during filtration?


  Particle size relative to filter pore size.
• What happens to solid particles during the filtration process?


  Solid particles get trapped by the filter.
• What is collected in the container during filtration?

  The filtrate, which is the liquid component.
• What is the residue in the filtration process?


  The solid particles that remain on the filter paper.
• When is filtration most useful?


  When separating solids from liquids or removing impurities.
• Which method would be most appropriate for separating sand from river water?

  Filtration.
• How can components of a mixture be separated?


  Components can be separated based on their physical properties like boiling point, solubility, or density.
• What is the basic principle of distillation?


  Distillation is a separation technique that uses differences in boiling points to separate components of a mixture.
• What are the key steps in the distillation process?


  1. Heating: Mixture is heated
  2. Vaporization: Components with lower boiling points turn into vapor first
  3. Condensation: Vapors are cooled and collected separately
  4. Separation: Different components are collected in different containers
• Why is distillation effective for separating alcohol from water?


  Because alcohol boils at a lower temperature (78°C) than water (100°C).
• What physical property allows distillation to separate components of a mixture?


  Different boiling points allow distillation to separate components.
• In a mixture of water and ethanol, why can these substances be separated by distillation?


  Because water and ethanol have different boiling points - water at 100°C and ethanol at 78°C.
• What is the definition of boiling point?


  • The temperature at which a liquid turns into a gas.
  • In distillation, components with lower boiling points vaporize first.
• How do boiling point differences affect distillation?


  Boiling point differences determine ease of separation, efficiency of distillation, and order of component collection.
• What are the main components of a distillation apparatus?


  1. Heating flask: Contains the original mixture
  2. Condenser: Cools vapors back to liquid
  3. Collection flask: Receives separated components
  4. Heat source: Provides energy to separate mixture
• What is the primary purpose of the condenser in a distillation apparatus?


  The condenser cools vapors back into liquid form for collection.
• What are the types of distillation?


  1. Simple distillation: Basic separation of two liquids
  2. Fractional distillation: Separates multiple components using a fractionating column
  3. Steam distillation: Used for heat-sensitive substances
  4. Vacuum distillation: Reduces pressure to lower boiling points
• What is evaporation?


  Evaporation is a physical process where a liquid changes into a gas at temperatures below its boiling point.
• What happens to molecules during evaporation?


  Molecules with the highest kinetic energy escape the liquid surface.
• At what temperature does evaporation occur?


  Evaporation occurs at any temperature above freezing.
• What factors affect the rate of evaporation?


  • Temperature
  • Surface area
  • Humidity
  • Air movement
• Which factor would increase the rate of evaporation?


  Increasing temperature.
• How does evaporation separate dissolved substances?


  Evaporation removes the liquid component, leaving behind dissolved solids.
• What are the steps in the evaporation process to separate a mixture?


  1. Heat the mixture
  2. Liquid turns to gas
  3. Dissolved substance remains as a solid residue