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).