Note:
Sometimes it is necessary to clean laboratory glassware, which can be done using a variety of methods. Glassware can be soaked in a cleaning solution to remove grease and remove most contaminants. These contaminants are then scrubbed with a brush or cleaning cloth to remove particles that cannot be rinsed. As an alternative to scrubbing, sturdy glassware may be able to withstand ultrasonic treatment. For some sensitive experiments, glassware may be soaked in a solvent, such as aqua regia or a weak acid, to dissolve trace amounts of specific contaminants known to interfere with the experiment. After cleaning is complete, it is common practice to rinse the glassware three times and then hang it upside down on a drying rack.