Salt preperation

• Acids


  React with metals, bases and carbonates to form salts
• Preparation of salt crystals from acids

  Depends on whether the substances they are reacting with are soluble or insoluble
• Preparation of a salt from a metal or insoluble base/carbonate

  1. Stage 1: Excess metal/base/carbonate is added to the acid

  2. Stage 2: The mixture is filtered using a filter funnel and filter paper

  3. Stage 3: The salt crystals are collected from the solution by evaporation
• Metals, bases and certain metal carbonates

  • Insoluble in water
• Excess metal/base/carbonate


  Added to the acid to make sure all the acid has reacted and been used up
• Heating and stirring


  Help the process
• Fizzing


  Stops when all the acid has been used up
• Evaporation rate


  Determines the size of the salt crystals produced
• Preparation of a salt from an alkali or soluble carbonate


  A titration is used to produce a salt from an acid and alkali
• Titration method


  1. Measure exactly 25 cm³ of alkali into a conical flask

  2. Add a few drops of indicator

  3. Place the flask onto a white tile

  4. Fill the burette with acid

  5. Slowly add the acid from the burette to the alkali until the indicator changes colour

  6. Record the volume of acid added

  7. Repeat steps 1-6 without using the indicator and adding the same volume of acid
• Indicator


  Used to determine the endpoint of the reaction
• Preparing Insoluble Salts


  1. Stage 1: Mixing the two soluble salt solutions

  2. Stage 2: Filtration to separate the insoluble precipitate

  3. Stage 3: Washing and drying the precipitate
• Insoluble salt


  Made when solutions of two soluble salts react in a precipitation reaction
• Concentration


  The number of moles per dm³
• Titration Calculation (1:1 mole ratio)

  1. Step 1: Convert all volumes to dm³

  2. Step 2: Calculate the number of moles of the substance where the volume and concentration are known

  3. Step 3: Calculate the unknown concentration
• Titration Calculation (2:1 mole ratio)


  1. Step 1: Convert all volumes to dm³

  2. Step 2: Calculate the number of moles of the substance where the volume and concentration are known

  3. Step 3: Calculate the unknown concentration
• how to convert to dm3

  Divide a volume in cm³ by 1,000 to convert to dm³