required practicals

• What is the process of filtration used for?

  To separate insoluble solids from liquids
• When is filtration particularly useful?

  When separating an insoluble solid from a liquid reaction mixture
• What does insoluble mean?

  The solid cannot be dissolved in the liquid
• What are soluble solids?

  Solids that can dissolve in a liquid
• What is the first step in evaporation?

  Pour the solution into an evaporating dish
• What happens during evaporation?

  The solvent evaporates, concentrating the solution
• What should you do after crystals begin to form during evaporation?

  Keep heating until only dry crystals remain
• When is crystallisation used instead of evaporation?

  When the salt decomposes when heated
• What is the first step in crystallisation?

  Pour the solution into an evaporating dish
• What occurs when the solution cools in crystallisation?

  Salt forms crystals as it becomes insoluble
• What is rock salt a mixture of?

  Salt and sand
• Why can salt be separated from sand?

  Salt dissolves in water, sand does not
• What are the steps to separate rock salt?

  1. Grind the mixture to make salt crystals small
  2. Dissolve in water and stir
  3. Filter the mixture to separate sand
  4. Evaporate water to obtain dry salt crystals
• What is simple distillation used for?

  To separate a liquid from a solution
• What happens during simple distillation?

  The part with the lowest boiling point evaporates first
• What is left behind in the flask after distillation?

  The rest of the solution
• What is a limitation of simple distillation?

  It only works for liquids with very different boiling points
• What is fractional distillation used for?

  To separate a mixture of liquids
• What is the role of the fractionating column in fractional distillation?

  It allows liquids to evaporate at different temperatures
• How does fractional distillation differ from simple distillation?

  Fractional distillation separates liquids with similar boiling points
• What happens when the thermometer matches the boiling point of a liquid in fractional distillation?

  The liquid evaporates and rises to the top
• What should you do after collecting the first liquid in fractional distillation?

  Raise the temperature to collect the next liquid
• How does filtration aid in purification?

  It separates solid impurities from liquids
• Why is grinding important in separating rock salt?

  It makes salt crystals small for easy dissolution
• Why is stirring important during the dissolving step?

  It ensures even distribution of salt in water
• What is the significance of cooling in crystallisation?

  It allows salt to become insoluble and form crystals
• How does temperature affect fractional distillation?

  Different temperatures cause liquids to evaporate