Mixtures

• What are the different methods to separate mixtures mentioned in the study material?

  Filtration, crystallisation, simple distillation, fractional distillation, and chromatography
• How does the method chosen for separating mixtures depend on the mixture?

  The method depends on the type of mixture being separated
• What is the definition of a pure substance in chemistry?

  • A pure substance consists only of one element or one compound.
  • It does not contain any other substances mixed together.
• What does the term 'element' refer to in chemistry?

  An element is a substance made of one type of atom only
• What is a compound in chemistry?

  A compound is a substance formed by the chemical union of two or more elements
• What is a mixture in chemistry?

  A mixture consists of two or more substances that are not chemically joined together
• How do the substances in a mixture behave in terms of their chemical properties?

  Being part of a mixture does not change the chemical properties of the substances
• What are the characteristics of physical processes used to separate mixtures?

  • Physical processes do not involve chemical reactions.
  • No new substances are made during the separation.
• What is the significance of the statement "The components of a mixture can be separated without chemical reactions"?

  It highlights that mixtures can be separated using physical methods
• What are the types of substances that can be found in a mixture?

  • Elements
  • Compounds
  • Both elements and compounds
• What are some methods used to separate mixtures?

  Filtration, crystallisation, simple distillation, fractional distillation, and chromatography
• What factors determine the method chosen for separating mixtures?

  • The type of mixture
  • The physical properties of the components
• What is the purpose of filtration?

  To separate an insoluble solid from a liquid
• How does filtration work?

  It uses a physical barrier, such as filter paper, to separate particles based on size
• What is an example of an insoluble solid?

  Sand
• What happens to the solid and liquid during filtration?

  The liquid passes through the filter paper while the solid is retained
• What is crystallisation used for?

  To produce solid crystals from a solution
• How does the process of crystallisation work?

  It involves evaporating the solvent to leave behind solid crystals
• What is an example of a substance obtained through crystallisation?

  Copper sulfate crystals
• What is the first step in the crystallisation process?

  Warming the solution to evaporate some of the solvent
• What are the steps to obtain large, regularly shaped crystals from crystallisation?

  1. Place the solution in an evaporating basin
  2. Warm the solution over a boiling water bath
  3. Stop heating when crystals form around the edge
  4. Pour away excess liquid after cooling
  5. Dry the crystals using a warm oven or filter paper
• What is the role of the solvent in crystallisation?

  The solvent dissolves the solute to form a solution
• What occurs during evaporation in the crystallisation process?

  The liquid changes state from liquid to gas, leaving solid crystals behind
• What is a crystal?

  A solid containing particles joined together in a regular arrangement
• What happens to the volume of the solution during crystallisation?

  The volume decreases as the solvent evaporates
• How does filtration differ from crystallisation in separating mixtures?

  Filtration separates solids from liquids, while crystallisation produces solid crystals from a solution
• What are the different methods to separate mixtures mentioned in the study material?

  Filtration, crystallisation, simple distillation, fractional distillation, and chromatography
• What factors determine the method chosen for separating mixtures?

  • Type of mixture
  • Desired purity of components
  • Physical properties of substances (e.g., boiling points)
• What is simple distillation used for?

  To separate a solvent from a solution
• Why is simple distillation useful for producing pure water from seawater?

  Because the dissolved solute has a much higher boiling point than the solvent
• What happens to the solvent during simple distillation when the solution is heated?

  The solvent vapor leaves the solution and is condensed back into liquid
• What is the definition of a solute?

  The dissolved substance in a solution
• What is the boiling point?

  The temperature at which a substance rapidly changes from a liquid to a gas
• What occurs to the remaining solution during simple distillation?

  The remaining solution becomes more concentrated as the amount of solvent decreases
• What are the steps involved in simple distillation?

  1. Heat the solution
  2. Solvent vaporizes
  3. Vapor moves to the condenser
  4. Vapor cools and condenses into liquid
  5. Collect the pure solvent
• What is fractional distillation used for?

  To separate different liquids from a mixture of liquids
• How does fractional distillation work?

  It separates liquids based on their different boiling points
• What is an example of a mixture that can be separated by fractional distillation?

  A mixture of ethanol and water
• What happens to vapors during fractional distillation?

  Vapors rise through a column that is hot at the bottom and cooler at the top
• How are different liquids collected in fractional distillation?

  By collecting them from different parts of the column or by continuing to heat the mixture