Acetone
Formula: C3H6O.
Molecular weight: 58.0791.
Boiling temperature: 56.1ºC.
Density: 0.7899 g/cm³.
CAS Number: 67-64-1.
Other names: 2-Propanone; β-Ketopropane; Dimethyl ketone; Dimethylformaldehyde; Methyl ketone; Propanone; Pyroacetic ether; (CH3)2CO; Dimethylketal; Ketone propane; Ketone.
Acetone is an important industrial solvent used for the purification of phenethylamines, cathinones and other substances. For purification applications, its quality requirements are very high, with a 99%+ content being desirable. Such acetone is not always available. It is highly discouraged to use low-quality acetone, it can cost the loss of all the yield obtained in the previous complex steps. Therefore, let's consider options for using construction acetone, which is used everywhere.
If the sticker shows % content, it means that the rest are impurities: water, methyl alcohol, acetone homologues, acetals.
Testing acetone at home.
Let's start with a simple one. At what concentration, acetone stops dissolving ABS plastic. Let's prepare 4 solutions of acetone 60%, 70%, 80%, 90%, add ABS plastic and leave it for 24 hours. After shaking:
You can see that the plastic dissolved only in 90% acetone. In other words, if acetone has more than 10% water, it will not work. Let's move on to another experiment: to test acetone, you will need copper sulfate, which you can freely buy in a fertilizer store. The blue crystals should be crushed into a powder and carefully heated (copper sulfate is poisonous, it should be done in a non-food pan under a hood and/or in the open air).
Pour the resulting powder with a small amount of acetone. Stir it around. If there is water in the acetone, the white powder will turn blue after a minute.
The comparison photo shows pure acetone and acetone with 20% water. If after one minute the color has not changed to blue, and the ABS plastic does not dissolve in this acetone, then we can safely say that this acetone is of very low quality, and it must be cleaned.
Purification :
A sealed distiller will be required to purify the acetone.
Acetone is very difficult to dry; the use of many of the commonly used drying agents (even MgSO4) leads to condensation of acetone. For drying, it is convenient to use molecular sieve 4A and K2CO3. Distillation over a small amount of KMnO4 can break down impurities in the acetone, such as aldehydes.
Very pure acetone is obtained as follows: saturate dry NaI (100g/400ml) at 25-30 °C, decant the solution and cool to -10 °C; NaI crystals form a complex with acetone, which is filtered and heated to 30 °C; the resulting liquid is distilled.
If a Drierite dryer is used, the water content of the acetone can be reduced to 0.001% or less. The acetone must be distilled beforehand to reduce the water content to 0.25%. Drierite (anhydrous CaSO4) offers the minimum acid and base catalysis of aldol formation and is the recommended drying agent for this solvent. Acetone was shaken with Drierite (25g/L) for several hours before it was decanted and distd from fresh Drierite (10g/k) through an efficient column, maintaining atmospheric contact through a Drierite drying tube. The equilibrium water content is about 10-2M. Anhydrous Mg(ClO4)2 should not be used as drying agent because of the risk of EXPLOSION with acetone vapour.
Rapid procedure:
Acetone is dried with anhydrous potash K2CO3 (about 5% of the weight of acetone) by heating the mixture for several hours under reflux, poured into another flask and distilled over a fresh desiccant. Metallic sodium and alkalis are unsuitable for drying acetone.
For use as a solvent in the oxidation of organic substances with potassium permanganate acetone is distilled in the presence of a small amount of potassium permanganate KMnO4 (until the solution turns violet), anhydrous potash K2CO3 is added to remove water.
Acetone is very hygroscopic, so it should be stored in a sealed container.
Formula: C3H6O.
Molecular weight: 58.0791.
Boiling temperature: 56.1ºC.
Density: 0.7899 g/cm³.
CAS Number: 67-64-1.
Other names: 2-Propanone; β-Ketopropane; Dimethyl ketone; Dimethylformaldehyde; Methyl ketone; Propanone; Pyroacetic ether; (CH3)2CO; Dimethylketal; Ketone propane; Ketone.
Acetone is an important industrial solvent used for the purification of phenethylamines, cathinones and other substances. For purification applications, its quality requirements are very high, with a 99%+ content being desirable. Such acetone is not always available. It is highly discouraged to use low-quality acetone, it can cost the loss of all the yield obtained in the previous complex steps. Therefore, let's consider options for using construction acetone, which is used everywhere.
If the sticker shows % content, it means that the rest are impurities: water, methyl alcohol, acetone homologues, acetals.
Testing acetone at home.
Let's start with a simple one. At what concentration, acetone stops dissolving ABS plastic. Let's prepare 4 solutions of acetone 60%, 70%, 80%, 90%, add ABS plastic and leave it for 24 hours. After shaking:
Purification :
A sealed distiller will be required to purify the acetone.
Acetone is very difficult to dry; the use of many of the commonly used drying agents (even MgSO4) leads to condensation of acetone. For drying, it is convenient to use molecular sieve 4A and K2CO3. Distillation over a small amount of KMnO4 can break down impurities in the acetone, such as aldehydes.
Very pure acetone is obtained as follows: saturate dry NaI (100g/400ml) at 25-30 °C, decant the solution and cool to -10 °C; NaI crystals form a complex with acetone, which is filtered and heated to 30 °C; the resulting liquid is distilled.
If a Drierite dryer is used, the water content of the acetone can be reduced to 0.001% or less. The acetone must be distilled beforehand to reduce the water content to 0.25%. Drierite (anhydrous CaSO4) offers the minimum acid and base catalysis of aldol formation and is the recommended drying agent for this solvent. Acetone was shaken with Drierite (25g/L) for several hours before it was decanted and distd from fresh Drierite (10g/k) through an efficient column, maintaining atmospheric contact through a Drierite drying tube. The equilibrium water content is about 10-2M. Anhydrous Mg(ClO4)2 should not be used as drying agent because of the risk of EXPLOSION with acetone vapour.
Rapid procedure:
Acetone is dried with anhydrous potash K2CO3 (about 5% of the weight of acetone) by heating the mixture for several hours under reflux, poured into another flask and distilled over a fresh desiccant. Metallic sodium and alkalis are unsuitable for drying acetone.
For use as a solvent in the oxidation of organic substances with potassium permanganate acetone is distilled in the presence of a small amount of potassium permanganate KMnO4 (until the solution turns violet), anhydrous potash K2CO3 is added to remove water.
Acetone is very hygroscopic, so it should be stored in a sealed container.
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