Commercially available absolute ethanol can generally only achieve 99.5% purity. In many reactions, higher purity anhydrous ethanol is required, and it is often necessary to prepare it yourself. Generally, 95.5% ethanol used in industry cannot directly produce absolute ethanol by distillation, because 95.5% ethanol and 4.5% water form a constant boiling point mixture. To remove the water, the first step is to add calcium oxide (quick lime) to boil and reflux, so that the water in the ethanol interacts with the quick lime to form calcium hydroxide, and then the absolute ethanol is distilled off. In this way, absolute ethanol is obtained with a purity of up to about 99.5%. Anhydrous ethanol of higher purity can be treated with metallic magnesium or metallic sodium.

Since the density of alcohol changes with the concentration, it is suitable for preparation after weighing. Calculate the mass of 95% and 5% of the total.
Use the beaker to weigh the amount of absolute ethanol needed.
Then add the calculated amount of water to the graduated cylinder and stir a few times to get 95% alcohol.

Pour 95ml of absolute ethanol and 5ml of water into the container to set 95% ethanol.

1. Anhydrous ethanol is very easy to absorb moisture from the air and can be miscible with water and various organic solvents 2113 such as chloroform and ether in any ratio.

2. Ethanol is an important organic solvent, which is widely used in various methods such as medicine, paint, hygiene products, cosmetics, oils, etc. 5261 accounts for about 410250% of the total ethanol consumption.

3. Commercially available absolute ethanol can generally only achieve 99.5% purity. In many reactions, higher purity absolute ethanol is required, and it is often necessary to prepare 1653 by yourself.

4. Absolute ethanol with higher purity can be treated with metallic magnesium or metallic sodium.