Preparation of Chromic Acid Cleaning Solution скачать в хорошем качестве

Preparation of Chromic Acid Cleaning Solution

Hi.Today we will prepare a chromic acid solution that is known as cleaning solution. The first step in preparing a chromic acid solution is to obtain a clean beaker and fill it with 5 grams of potassium dichromate (K2 Cr2 O7). Next add a small amount of water to the beaker and stir with a glass stirring rod to make a paste. While continuously stirring, carefully pour 100 milliliters of concentrated sulfuric acid (H2 SO4 (aq)) to the beaker. Since we are working with acids, you have to wear rubber gloves. The temperature will rise to 70-80oC. And we will leave it to cool. Finally, pour the chromic acid into a glass storage container with a stopper. Be sure to put a label on the glass storage container indicating it contains concentrated chromic acid and the date it was made. We should keep it in dark. After we can use it to clean the glassware until its colour becomes greenish.