Recipes for Preparing Glassware Cleaning Solutions Dichromate Sulfuric Acid

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Recipes for Preparing Glassware Cleaning Solutions Dichromate Sulfuric Acid Powered By Docstoc
					                 Recipes for Preparing Glassware Cleaning Solutions

Dichromate – Sulfuric Acid ( Chromic Acid):

NOTE: USE EXTREME CAUTION WHEN PREPARING AND WORKING WITH THIS
SOLUTION. CONCENTRATED SULFURIC ACID IS VERY DANGEROUS. BE PREPARED
TO COOL THE SOLUTION SINCE IT BECOMES VERY HOT DURING PREPARATION.

Method 1:

   1. Dissolve 90 – 100 g of sodium or potassium dichromate in 450 ml of water.
   2. Add 80 ml of concentrated sulfuric acid. (the solution will become a semisolid red
      mass).
   3. Add just enough sulfuric acid to dissolve the mass.

Method 2:

   1. Add the contents of a 25 – ml bottle of Monostat “Chromerge” to a standard 9 – lb
      bottle of concentrated sulfuric acid.
   2. Add approximately 5 ml at a time, and shake well after each addition.

Additional Note: This solution is reusable, but will lose its effectiveness as it turns green.
When this happens, it should be discarded.

Alcoholic KOH (or NaOH)

   1. Dissolve 105 g of KOH (or 120 g NaOH) in 120 ml of water.
   2. Add 1 L of 95% ethanol (or propanol) (950 ml ethanol 50 ml water) and shake well.
      (this solution will etch glass to a small extent and therefore should not be left in
      contact with volumetric glassware or ground glass joints for more than about 15
      minute at a time).

				
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