Preparing Lead (II) Sulfate


This practical lesson covers:

  1. How to prepare a sample of pure, dry lead(II) sulfate

Preparation of a pure, dry sample of lead (III) sulfate


Aim

To prepare a sample of pure, dry lead (II) sulfate using filtration. 

Background information

Lead (II) sulfate is an insoluble salt formed by the reaction between lead nitrate and potassium sulfate. This reaction produces a precipitate of lead sulfate, which can be separated and purified using filtration. In this practical, you will prepare a sample of pure, dry lead (II) sulfate by mixing lead nitrate and potassium sulfate solutions, filtering the precipitate, and drying it.

Equipment

  1. Digital mass balance
  2. Evaporating dish
  3. Glass rod
  4. Measuring cylinder
  5. Drying oven
  6. Filter paper and funnel
  7. 250 cm3 beaker
  8. 250 cm3 conical flask

Method

  1. Add 75 cm3 lead nitrate to a beaker. 
  2. Add 75 cm3 potassium sulfate to the beaker and mix well using a glass rod. You should see a precipitate form.
  3. Place the filter paper in the funnel and place it in the top of a conical flask. 
  4. Pour the lead nitrate and potassium sulfate mixture into the funnel.
  5. Use deionised water to wash any solid out of the beaker. Wash the filtrate using deionised water to remove any potassium nitrate left.
  6. Measure the mass of an empty evaporating dish.
  7. Empty contents of filter paper into an evaporating dish. 
  8. Place evaporating dish in the drying oven. 
  9. When the lead (II) sulfate crystals are dry, place the evaporating dish on the balance to record the mass. 
  10. Calculate the mass of lead (II) sulfate formed. 

Safety

  1. Lead sulfate is toxic. Wash hands immediately if in contact with lead sulfate. 
  2. Lead nitrate is an irritant. Avoid touching lead nitrate with bare hands and wash hands immediately if skin is in contact with lead nitrate. 

What equipment is used to measure the mass of the evaporating dish and lead (II) sulfate crystals?

digital mass balance

measuring cylinder

glass rod

drying oven

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What substance is used to wash any solid out of the beaker and the filtrate?

potassium sulfate

deionised water

lead sulfate

lead nitrate

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Where should you place the evaporating dish containing the contents of the filter paper?

in the drying oven

on the glass rod

on the digital mass balance

in the conical flask

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Which of the following is a safety precaution that should be taken during this experiment?

hands should not be washed after contact with lead sulfate

hands should be washed immediately if in contact with lead sulfate

lead nitrate should be touched with bare hands

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What should you do after the lead (II) sulfate crystals are dry?

add 75 cm3 potassium sulfate to the beaker

place the evaporating dish on the balance to record the mass

wash the filtrate using deionised water

place the evaporating dish in the drying oven

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