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Why can't I dry/concentrate ethanol using calcium chloride ... or can I?
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Maha Ch
Why can't I dry/concentrate ethanol using calcium chloride ... or can I?
Yes, I think that lower alcohols cannot be dried using $\ce{CaCl2}$ as they form stable complexes with it but higher alcohols can be dried using $\ce{CaCl2}$ as they form unstable complexes while water forms stable complex. On the other hand,
aromatic alcohols like phenols can't be dried using $\ce{CaCl2}$ as they are somewhat acidic in nature.
At the same time, I assume that all salts wouldn't do the same thing with lower alcohols as each salt-alcohol complex has its own degree of stability and the salt-water complex may be more stable than the former. So, I don't recommend $\ce{CuSO4}$ as a drying agent.
Yes, I think that lower alcohols cannot be dried using $\ce{CaCl2}$ as they form stable complexes with it but higher alcohols can be dried using $\ce{CaCl2}$ as they form unstable complexes while water forms stable complex. On the other hand,aromatic alcohols like phenols can't be dried using $\ce{CaCl2}$ as they are somewhat acidic in nature.
At the same time, I assume that all salts wouldn't do the same thing with lower alcohols as each salt-alcohol complex has its own degree of stability and the salt-water complex may be more stable than the former. So, I don't recommend $\ce{CuSO4}$ as a drying agent.
Calcium chloride forms addition compounds with the alcohols. On evaporating a solution in ethyl alcohol at a low temperature rectangular plates of $\ce{2CaCl2.7C2H5OH}$ are deposited. The compounds $\ce{CaCl2.3C2H5OH}$ and $\ce{CaCl2.CH3OH}$ have also been separated, as well as a mono- and a di-acetone compound, and compounds with isobutyl and amyl alcohols.
So, if you are working with a cold solution of $\ce{C2H5OH}$ with $\ce{CaCl2}$ exposed to air undergoing evaporation, it is possible to form an addition compound (taking the form of rectangular plates) with the formula, $\ce{2CaCl2.7C2H5OH}$ or $\ce{CaCl2.3C2H5OH}$.
Calcium chloride forms addition compounds with the alcohols. On evaporating a solution in ethyl alcohol at a low temperature rectangular plates of $\ce{2CaCl2.7C2H5OH}$ are deposited. The compounds $\ce{CaCl2.3C2H5OH}$ and $\ce{CaCl2.CH3OH}$ have also been separated, as well as a mono- and a di-acetone compound, and compounds with isobutyl and amyl alcohols.
So, if you are working with a cold solution of $\ce{C2H5OH}$ with $\ce{CaCl2}$ exposed to air undergoing evaporation, it is possible to form an addition compound (taking the form of rectangular plates) with the formula, $\ce{2CaCl2.7C2H5OH}$ or $\ce{CaCl2.3C2H5OH}$.
Yes, I think that lower alcohols cannot be dried using $\ce{CaCl2}$ as they form stable complexes with it but higher alcohols can be dried using $\ce{CaCl2}$ as they form unstable complexes while water forms stable complex. On the other hand, aromatic alcohols like phenols can't be dried using $\ce{CaCl2}$ as they are somewhat acidic in nature.
At the same time, I assume that all salts wouldn't do the same thing with lower alcohols as each salt-alcohol complex has its own degree of stability and the salt-water complex may be more stable than the former. So, I don't recommend $\ce{CuSO4}$ as a drying agent.
Yes, I think that lower alcohols cannot be dried using $\ce{CaCl2}$ as they form stable complexes with it but higher alcohols can be dried using $\ce{CaCl2}$ as they form unstable complexes while water forms stable complex. On the other hand,aromatic alcohols like phenols can't be dried using $\ce{CaCl2}$ as they are somewhat acidic in nature.
At the same time, I assume that all salts wouldn't do the same thing with lower alcohols as each salt-alcohol complex has its own degree of stability and the salt-water complex may be more stable than the former. So, I don't recommend $\ce{CuSO4}$ as a drying agent.
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The apparent answer is yes, to quote from a source (composed from extracts of old chemistry journal):
So, if you are working with a cold solution of $\ce{C2H5OH}$ with $\ce{CaCl2}$ exposed to air undergoing evaporation, it is possible to form an addition compound (taking the form of rectangular plates) with the formula, $\ce{2CaCl2.7C2H5OH}$ or $\ce{CaCl2.3C2H5OH}$.
The apparent answer is yes, to quote from a source (composed from extracts of old chemistry journal):
So, if you are working with a cold solution of $\ce{C2H5OH}$ with $\ce{CaCl2}$ exposed to air undergoing evaporation, it is possible to form an addition compound (taking the form of rectangular plates) with the formula, $\ce{2CaCl2.7C2H5OH}$ or $\ce{CaCl2.3C2H5OH}$.
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