Procedure Notes - Caffeine Caution In this experiment, you will be using methylene chloride, which is extremely volatile. It has a boiling point of 40 C, so it does not take much heat to convert it to a gas. You must vent it, often at first, less frequently as the extraction progresses. Also use caution when heating/ evaporating in the hood. Preparing the Tea Solution 1.) Place 15 mL of water in a 50-mL beaker, cover with a watch glass and heat on a hot plate until almost boiling. Place a tea bag in the hot water carefully so that it lies flat on the bottom of the beaker. Heat for 15 minutes. 2.) The screw cap centrifuge tubes we will be using only hold ~ 12 mL’s of volume so we will not be transferring all of the tea solution into the two centrifuge tubes as the text suggests. Extraction and Drying1.) Make sure centrifuge is balanced before use. 2.) If an emulsion still remains after centrifuging 1sttime, centrifuge again.
This is the end of the preview.
access the rest of the document.
Laboratory glassware, Erlenmeyer flask, arm flask, arm erlenmeyer flask