Actions to take/ overcome it
Corrosive- because ethanoic anhydride is corrosive you must make sure to handle with care when dealing with this solution and ALWAYS wear eye protection to ensure that none of enters your eyes or comes into contact with skin.
Corrosive- It causes burns.
It reacts violently, becoming very hot, when mixed with water.
It decomposes if heated strongly, forming toxic oxides of
Harms glass can cause when broken:
Cuts-from broken glass, flying glass, forcing
Burns- from heated glass.
Poisoning- following cuts by contaminated glassware.
To avoid all these incidents make sure you are careful when handling glassware. Make sure to place them in the middle of tables instead of edges where they are prone to falling.
Coats and Bags
If you’re not careful where you place your coats and bags it can become a potential hazard as you risk tripping over someone being yourself or your classmates. To avoid this you need to place your coats and bags somewhere which is away from where anyone is working and away from floors and hanging from tables.
Chairs and Tables
The chairs and tables need to be in a way as such that the do not interfere while you carry out the titration. If chairs and tables are placed in a wrong way it can trip up and hurt individuals. You must insure you avoid these accidents by carrying out the experiment standing up and also tucking the chairs in.
Firstly make sure all your equipment is dry as ethanoic acid reacts with water and this may affect your results. Weigh out 1g of 2-hydroxybenzoic acid using the weighing boat and balance and place this into a flask. Then measure out 2cm3 of ethanoic anhydride using a measuring flask and put this into the same flask as the 2-hydroxybenzoic acid. Then using the pipette put about 7-8 drops of phosphoric acid into the flask alongside the other substances, The phosphoric acid acts as a catalyst.
Put a condenser on the flask. In a fume cupboard, warm the mixture in a hot water bath, with swirling, until all the solid has dissolved and then warm until all the solids have completely dissolved in the boiling water.
Carefully add 5 cm3 of cold water to the solution. Stand the flask in a bath of iced water until precipitation appears to be complete. It may be necessary to stir vigorously with a glass rod to start the precipitation process. Filter off the product using a Buchner funnel and suction apparatus.
Wash the product with a little cold water, transfer to a weighed watch glass and leave to dry overnight to allow the aspirin to form. If aspirin does not form scratch the walls using a stirring rod. Weigh your product to later compare your results. Make sure to keep observations of the experiment throughout.
Thin layer chromatography
Thin layer chromatography is a technique which is used to separate different mixtures.
Firstly start by marking the starting point of each of your samples on the TLC plate using a pencil (never a pen as it smudges and runs on the TLC). Label the starting points with either alphabets or numbers whilst at the same time also making sure that they are all spread out. Using a spotter place the samples onto their designated areas making sure not to damage the TLC with the spotter. Place filter paper into the beaker and put elutant solvent (ethyl ethonoate) into a beaker with the filter paper. Make sure the solvent is below the pencil markings of the TLC that is also going to be placed inside the beaker. Shake the beaker to help the vapour be spread into the air inside the beaker. Using a pair of tweezers place the TLC…