mixtures

• What is the difference between pure substances and mixtures?

  Pure substances consist of one element or compound
• What are the properties of pure substances?

  They have a fixed composition and constant properties
• What are the properties of mixtures?

  They have variable composition and variable properties
• What are the three types of mixtures?

  Homogeneous mixtures, heterogeneous mixtures, solutions
• How do solutions differ from suspensions and colloids?

  Solutions have particles that are uniformly distributed

  
• What are the types of solutions based on physical states?

  Solid in liquid, solid in solid, gas in liquid
• What is the effect of temperature on solubility of solids in water?

  Higher temperatures generally increase solubility
• What separation technique would you use for a mixture based on particle size?

  Filtration
• What are the steps in extracting sucrose from sugar cane?

  • Crushing
  • Precipitation
  • Filtration
  • Vacuum distillation
  • Crystallisation
  • Centrifugation
• What is a pure substance?

  A substance made of one element or compound
• What is a mixture?

  A combination of two or more substances
• How can mixtures be separated?

  By physical processes without chemical reactions
• What is the difference in melting points between pure substances and mixtures?

  Pure substances have a sharp melting point
• What is a homogeneous mixture?

  A mixture with uniform distribution of components

  
• What is a heterogeneous mixture?

  A mixture with non-uniform distribution of components
• How do homogeneous and heterogeneous mixtures differ in composition?

  Homogeneous mixtures have uniform composition

  
• What is a solution?

  A homogeneous mixture of solute and solvent
• What are the types of solutions based on solute and solvent states?

  Solid, liquid, and gaseous solutions
• What is a dilute solution?

  A solution with a small amount of solute
• What is a concentrated solution?

  A solution with a large amount of solute
• What is an aqueous solution?

  A solution where the solvent is water
• What is a non-aqueous solution?

  A solution where the solvent is not water
• What is the purpose of purification?

  To separate mixtures into pure substances
• What is filtration used for?

  Separating insoluble solids from liquids
• How does chromatography work?

  It separates substances based on solubility differences
• What is the purpose of Rf values in chromatography?

  To identify components of mixtures
• What is crystallisation?

  Separation of dissolved solids as well-formed crystals

  
• What is simple distillation used for?

  Separating pure liquid from a solution
• What is fractional distillation?

  Separating miscible liquids with different boiling points
• What is sublimation?

  Separation of solids by turning one into vapor
• What is the use of a separating funnel?

  To separate immiscible liquids
• How can purity of substances be checked?

  By measuring fixed melting and boiling points
• What happens to impure substances' melting and boiling points?

  They melt and boil over a range of temperatures
• How does the presence of salt affect the boiling point of water?

  It raises the boiling point above 100°C