Guide Questions (9)

• What is the advantage of using calcium chloride

  solution as precipitant with other solution?

  Calcium chloride is effective because it reacts readily with carbonate ions to form a solid precipitate of calcium carbonate.
• What is the advantage of using calcium chloride

  solution as precipitant with other solution?

  These are easy to filter and weigh accurately.
• List three possible sources of error that would

  cause the molar mass of the unknown to be:ately.

  Too high

  1. Incomplete drying of the precipitate
  2. Contamination with other compounds
  3. Excess calcium chloride causing unreacted material in the precipitate.
• List three possible sources of error that would

  cause the molar mass of the unknown to be:

  Too low

  1. Loss of precipitate during filtration
  2. Insufficient precipitation due to incorrect pH
  3. Incomplete reaction
• How could you improve this experimental

  procedure to reduce the likelihood of error?

  Explain.

  Ensure complete precipitation by controlling pH.
• How could you improve this experimental

  procedure to reduce the likelihood of error?

  Explain.

  Thoroughly wash and dry the precipitate to remove

  impurities and moisture.
• How could you improve this experimental

  procedure to reduce the likelihood of error?

  Explain.

  Handle the precipitate carefully to avoid loss during

  filtration.