WM.5 Flashcards
Principles of green chemistry
What is the aim of green chemistry?
To develop chemicals and chemical processes that are as sustainable and as environmentally friendly as possible.
What are three key factors to consider for any chemical process?
- Cost
- Impact on the environment
- Health and safety
Is it possible to have a chemical process that holds all 12 green principles?
It is almost impossible, therefore chemists are continually finding balance between cost, impact on environment and health and safety.
What are three main techniques for purifying and/or identifying organic solids?
- Recrystallization
- Thin layer chromatography (TLC)
- Melting point determination
In the recrystallization of a solid crude organic product, what should be specified about the solvent used?
It should be hot, and it should be a solvent that only the desired product dissolves in, this way any insoluble impurities can be filtered off.
How are soluble impurities and the desired product separated?
On cooling, the desired product will crystallize out, leaving the soluble products still in the solution. The crystals of products should then be filtered out, washed and dried.
What is TCL used for?
Separating small quantities of organic compounds, or to check the purity of organic substances.
What material is the plate in TCL?
Silica, Al2O3, it has a white color.
Can any solvent be used in TCL?
No, a suitable solvent must be chosen, this is because different organic compounds have different preference for solvents and travels at different rates through phases.
What value should the melting point of your organic compound be within the published value for it to be considered pure?
0.5℃
