Separation methods

Question 1

Explain filtration

Answer 1

• Used to separate a liquid and an insoluble solid
• Run the mixture through a filter funnel and filtration paper
• Only water can go through the filtration paper

Question 2

Explain evaportion (seperation)

Answer 2

• Used to separate soluble solid and liquid solution
• Heat solution in evaporating dish untill all solution has evaporated and crystals have been formed
• Pros: quick and easy
• Cons: some solids undergo thermal decompostion when heated

Question 3

Explain crystalisation

Answer 3

• Used to seperate soluble solid and liquid solution (used if solid will decompose)
• Gently heat solution in evaporating dish until some crystals have formed. Stop heating and allow more crystals to form (solids are less soluble at cooler temperatures).
• Filter remaining solution to sperate crystals. Dry crystals by leaving them somewhere warm

Question 4

Explain simple distillation

Answer 4

• Used to separate a liquid from a solution
• Solution is held in a flask which is covered so no gas can escape
• Flask is heated to the bioling point of one of the liquids. As one liquid condenses, it moves up the flask and then down the condenser which is inside of a water jacket to keep the condenser cool
• Condenser causes the gas to condense into a liquid and collect in a beaker

Question 5

Explain fractional distillation

Answer 5

• Used to separate mixtures of liquids
• Solution is heated in flask however, when moving up the flask it encounters a fractionating column
• Fractionating column has lots of glass rods to increase surface area and gets cooler near the top
• As moving up the column, any other liquids that were also evaporated comes into contact with the glass rods and condenses back into liquid, falling down into the original solution