How do you dry cobalt chloride?
Procedure
- Dissolve 5 g of hydrated cobalt(II) chloride in 100 cm3 of water (solution is TOXIC).
- Soak filter paper in this solution, drain and dry in an oven (set at no more that 100 °C), so that it is a definite blue colour.
- The filter paper can be cut into small strips and stored in a desiccator with dry silica gel.
Is cobalt chloride a desiccant?
Cobaltous chloride is added to silica gel and activated alumina type desiccant as a moisture indicator. It has also been used in indicator paper.
Is cobalt chloride a drying agent?
Nowadays, cobalt chloride (CoCl2) is important technically as a moisture indicator, for example in silica gel. Silica gel is colorless amorphous silicon dioxide and has a gel-like to solid consistency. It is strongly hygroscopic and is often used as a drying agent.
What is the most powerful desiccant?
Molecular sieve
Molecular sieve is the best desiccant based on technical performance characteristics. Its ability to adsorb moisture, in this case water vapor, is so pronounced that it can remove trapped H20 molecules from a fully saturated silica gel bead, which in turn changes the silica gel back to its original Cobalt blue color.
Why does cobalt chloride turn pink in water?
nH2O . It easily undergoes hydration and dehydration causes the colour change and thus it is used as the indicator for water in desiccants. Cobalt chloride changes the colour in response to the humidity. As the humidity increases the cobalt chloride changes the colour from sky blue to the purple and then to the pink.
Is cobalt chloride a carcinogen?
Cobalt chloride (CAS No. 7646-79-9) is classified as hazardous: Category 2 carcinogenic substance, with the risk phrase ‘May cause cancer by inhalation’ (T; R49) in HSIS (Safe Work Australia).
Is cobalt chloride safe?
What is cobalt chloride used for?
Commercially, cobalt (II) chloride is often used to make sealants, adhesives, and glues. It is also used for electroplating, particularly for plating objects with cobalt metal. Surface treating metal is another common industrial use of the compound.
Is cobalt chloride toxic?
A suspected carcinogen and very toxic. Cobalt chloride attacks the blood, liver, thyroid, lungs and connective tissues. It is an eye and respiratory tract irritant and a skin sensitiser. Eye contact causes redness and pain.
What is a good drying agent?
1. Calcium chloride (n=6) is a very good drying agent for a broad variety of solvents but is generally not compatible with hydroxy (alcohol, phenol), amino (amine, amide) and carbonyl (acid, ketone, ester) functions due to basic impurities such as Ca(OH)2 and CaCl(OH).
What happens when you heat hydrated cobalt chloride?
Heating pink hydrated cobalt(II) chloride makes it turn blue.
Is cobalt chloride harmful to humans?
How much cobalt chloride is toxic?
Toxicity Cobalt chloride is only moderately toxic by ingestion although a 19 month-old child died some six hours after allegedly drinking only 30 mL (Jacobziner and Raybin, 1961). In another report a six year-old developed only transient gastrointestinal upset after ingesting 2.5 g (Mucklow et al, 1990).
Why is cobalt harmful to humans?
* Cobalt may cause an asthma-like allergy. Future exposure can cause asthma attacks with shortness of breath, wheezing, cough, and/or chest tightness. * Cobalt may affect the heart, thyroid, liver and kidneys. * Repeated exposure to Cobalt dust can cause scarring of the lungs (fibrosis) even if no symptoms are noticed.
Is it possible to add too much drying agent?
Try to avoid large a large excess of drying agent since it will lead to the loss of product. There is a competition of water or your compound absorbing on the drying agent. Generally, water has a higher affinity towards the drying agent, but a large excess of drying agent also causes youor compound to absorb.
What are drying solvents?
Solvent drying involves the use of a drying agent to remove excess water from an organic solvent. This is different from solvent evaporation which is a process that reduces the solvent volume through vaporization.