Filtration, Evaporation & Crystallisation

• What techniques can be used to separate soluble and insoluble solids from liquids?

  Filtration, evaporation, and crystallization
• What is formed when a solid does not dissolve in a liquid?

  A mixture between a liquid and an insoluble solid
• What is an example of an insoluble solid in water?

  Sand
• What do we call a liquid that contains a soluble solid dissolved in it?

  A solution
• In a solution of sodium chloride in water, what is the solute?

  Sodium chloride
• What is the role of filter paper in the filtration process?

  To allow liquids to pass through while retaining solids
• What is the first technique used to separate insoluble solids from liquids?

  Filtration
• How does filtration in chemistry differ from using a sieve in cooking?

  Filtration uses filter paper with tiny holes to separate solids from liquids
• What happens to a soluble solid when it is dissolved in a liquid?

  It forms a solution
• What is the purpose of evaporation in separating a soluble solid from a liquid?

  To remove the solvent and leave behind the solid
• What equipment is typically used for evaporation in a laboratory setting?

  An evaporating dish or a crucible
• What is the effect of heating a solution during evaporation?

  It causes the solvent to evaporate and the solution to become more concentrated
• What is thermal decomposition?

  When some solids break down into different substances when heated
• Why might crystallization be preferred over evaporation for some solids?

  Because some solids decompose when heated
• What is the first step in the crystallization process?

  To place the solution into an evaporation dish and heat it gently
• What happens to the solubility of solids as the temperature decreases during crystallization?

  Solids become less soluble at colder temperatures
• What is the final step after filtering out crystals in the crystallization process?

  To dry the crystals
• What are the steps involved in the crystallization process?

  1. Place the solution in an evaporation dish and heat gently.
  2. Allow some solvent to evaporate and crystals to form.
  3. Stop heating and let the solution cool.
  4. Filter out the crystals using filter paper and funnel.
  5. Dry the crystals by leaving them warm or using an oven.
• What are the advantages and disadvantages of evaporation and crystallization for separating solids from solutions?

  Advantages of evaporation:

  • Quick and easy method.

  
  

  Disadvantages of evaporation:

  • Some solids may decompose when heated.

  
  

  Advantages of crystallization:

  • Suitable for solids that decompose upon heating.

  
  

  Disadvantages of crystallization:

  • Slower than evaporation.