How do you distill a DCM?
Distillation of dichloromethane TIMING ~6 h Stir the mixture using a magnetic stir bar and heat the reaction flask to 80°C using a heating mantle. Collect the first 30 mL distillate in the 100 mL receiving flask and then replace with a 1000 mL receiving flask.
How do you dry DCE?
Dichloromethane (DCM) and dichloroethane (DCE) were dried by refluxing over CaH2 under N2(g). N-methylpyrrolidinone (NMP) and ethanol were used as commercially supplied (anhydrous/reagent grade). Petroleum spirit (PS, 40-60°C fraction), n-hexane and water (H2O) were purified by distillation.
How do you quench calcium hydride?
Slowly add isopropanol to quench calcium hydride. Upon completion, add ethanol or methanol as a more reactive quenching agent to ensure completion. Finally, add water dropwise to make sure there are no pockets of reactive materials.
How do you dry DCE solvent?
Add sodium wire and benzophenone to a volume of THF (pre-dried over calcium hydride or 4A molecular sieves), heat at reflux/under nitrogen for several hours until the solvent turns deep blue in colour. This indicates the solvent is dry, and you can distill off the volume you require.
What metal is used in solvent stills?
Solvent flasks containing lithium aluminum hydride must never be heated. As a drying agent lithium aluminum hydride is therefore only suitable for non-reducible solvents that can be obtained pure by flask-to-flask vacuum-transfer at ambient temperature.
Can you pour calcium hydroxide down the drain?
Note that whilst clean calcium hydride is safe (once quenched) to be disposed of via the normal drainage, you must ensure any chemicals are washed off first (hexane works well), especially odorous things such as amines which you may have been drying with the calcium hydride.
What happens if I touch sodium metal?
Contact of metallic sodium with the skin, eyes, or mucous membranes causes severe burns; thermal burns may also occur due to ignition of the metal and liberated hydrogen.
How do you make a dry solvent?
Dry DMF can be prepared by drying overnight over barium oxide or 4A molecular sieves, followed by decantation of the drying agent and vacuum distillation (~20 mmHg is a sufficient vacuum to lower the boiling point over DMF to a reasonable value). Dry DMF can be stored over 4A molecular sieves.
How do you store calcium hydroxide?
Store in a cool, dry, well-ventilated, locked store room away from incompatible materials. Use ventilation to keep airborne concentrations below exposure limits. Have approved eyewash facility, safety shower, and fire extinguishers readily available.
What happens if the temperature is too high during distillation?
If a mixture is heated too rapidly the rising vapor will have a chance of being carried over to the receiver without condensing. Thus, more higher-boiling material will be found mixed in with the lower boiling material.
What can go wrong with distillation?
The distillation result is poor: the fractions obtained are not of acceptable purity. Typical problems: Distillation too fast. The components require time to separate. We need many evaporation-condensation cycles for good separation, and pseudo-equilibrium between vapor and liquid throughout the system.
Which catalyst is used in EDC manufacturing?
2. Ethylene Oxychlorination Catalysts
| year | catalysts | EDC selectivity (%) |
|---|---|---|
| 2016 | CeO2–ZrO2 | 45 |
| 2017 | RuO2 | 55 |
| 2018 | CeCl3 | 10 |
| CeOCl | 8 |
What are the hydrolysis products of calcium hydride?
The two hydrolysis products, gaseous H 2 and Ca (OH) 2, are readily separated from the dried solvent. Calcium hydride is a relatively mild desiccant and, compared to molecular sieves, probably inefficient. Its use is safer than more reactive agents such as sodium metal or sodium-potassium alloy.
Is calcium hydride a desiccant?
?) Calcium hydride is the chemical compound with the formula CaH 2, and is therefore an alkaline earth hydride. This grey powder (white if pure, which is rare) reacts vigorously with water liberating hydrogen gas. CaH 2 is thus used as a drying agent, i.e. a desiccant.
How is calcium hydride prepared from its elements?
Calcium hydride is prepared from its elements by direct combination of calcium and hydrogen at 300 to 400 °C. CaH 2 is a reducing agent for the production of metal from the metal oxides of Ti, V, Nb, Ta, and U.
What is the standard state of calcium hydride at 25 degrees Celsius?
[Ca+2] Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).?) Calcium hydride is the chemical compound with the formula CaH 2, and is therefore an alkaline earth hydride.