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How to Make a Corrosive Sublimate

Corrosive sublimate is another name for mercuric chloride. At one time, it was the preferred method of treating syphilis, but was replaced by safer methods due to its toxicity. It is currently used as a pesticide, antiseptic or wood preservative. The main application, though, is as a catalyst for converting acetylene into vinyl chloride.

Things You'll Need

Safety glasses
Rubber gloves
Mercurous nitrate
Glass beaker
Bunson burner
Thermometer
Hydrochloric acid or mercury sulfate
Salt
Alcohol

Instructions

Hydrochloric Acid and Mercurous Nitrate
- 1
  Put on safety glasses and rubber gloves.
- 2
  Fill a glass beaker halfway with a solution of mercurous nitrate.
- 3
  Place a thermometer in the beaker, and heat the contents to a temperature of 288 to 303 degrees F with a Bunson burner.
- 4
  Add hydrochloric acid to the beaker. There will be a spontaneous reaction that looks like this: HgNO3 + 2 HCl ͛4; HgCl2 + H2O + NO2. The solid corrosive sublimate (white crystals) will precipitate from the solution.
Salt and Mercury Sulfate
- 5
  Add equal parts table salt (NaCl) and mercury sulfate (HgSO4) to a beaker.
- 6
  Place the beaker over a Bunson burner, and heat it until it starts to off-gas.
- 7
  Check the resulting reaction of the NaCl + HgSO4 ͛4; HgCl2 + Na2SO4.
- 8
  Fill the beaker with water, and the Na2SO4 will dissolve. The sublimate (HgCl2) will remain at the bottom of the beaker.
- 9
  Pour out the liquid, and refill the beaker a second time. Pour it out again. The remaining solid will be the corrosive sublimate.

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