Question: Interactions: Summarize this section (in the book) in your own words and for each interaction give a complete sentence.
The strength of interactions of eluted compounds with alumina or silica gel depends on how strongly they are adsorbed to the adsorbants. I will list these interactions in decreasing order of strength and presuming a slightly basic alumina or silica gel.
The strongest interaction is salt formation and it comes about when acidic substances directly interact with alumina to the extent that it is dissolved and so salts are formed.
Coordination interactions are also direct interactions involving coordinate covalent bonds that share electrons and is a strong interaction.
Hydrogen bonding comes about when materials capable of hydrogen bonding (H atom bonded to F, O, or N) directly interact with the oxygen atoms of alumina or the silica gel.
Dipole-dipole interactions are not direct interactions and are due to dipole polar induced interactions. These are the weakest of the important interactions.
Van der Waals are weak forces that involve nonpolar molecules that do not bind strngly unless they have extremely high molecular weights.
Does this look okay? I realize you don't know what's in the book but if there are any glaring errors, I'd like to know.
Thanks from Sheryl
I should have added at the beginnning:
The more polar the functinal group, the stronger the bond to alumina or silica and the more soluble the polar compound.
That seems to be the point of this section.
S
Question: Interactions: Summarize this section (in the book) in your own words and for each interaction give a complete sentence.
The strength of interactions of eluted compounds with alumina or silica gel depends on how strongly they are adsorbed to the adsorbants. I will list these interactions in decreasing order of strength and presuming a slightly basic alumina or silica gel. Does the question ask you to list them in decreasing order of strength? If not, I would strike that sentence because if the question doesn't ask for that and you get one of them out of line you have set yourself up for a few points to be subtracted from your score.
The strongest interaction is salt formation and it comes about when acidic substances directly interact with alumina to the extent that it is dissolved and so salts are formed. It isn't clear what "it" is. See ....."with alumina to the extent that IT is dissolved........" You could be talking about the eluting material or the silica gel (or the sample).
Coordination interactions are also direct interactions involving coordinate covalent bonds that share electrons and is a strong interaction.
Hydrogen bonding comes about when materials capable of hydrogen bonding (H atom bonded to F, O, or N) directly interact with the oxygen atoms of alumina or the silica gel.
Dipole-dipole interactions are not direct interactions and are due to dipole polar induced interactions. These are the weakest of the important interactions.
Van der Waals are weak forces that involve nonpolar molecules that do not bind strngly unless they have extremely high molecular weights.
Does this look okay? I realize you don't know what's in the book but if there are any glaring errors, I'd like to know.
It looks ok to me; at least I don't see anything glaring. You might consider replacing the "comes about" phrase with "occurs" and see if that sounds better. Also, I would definitely include the add-on you wrote in your follow up post.
The summary of the section in the book is as follows:
The strength of interactions between eluted compounds and alumina or silica gel depends on how strongly they are adsorbed to the adsorbents. In decreasing order of strength, the interactions are: salt formation, coordination interactions, hydrogen bonding, dipole-dipole interactions, and Van der Waals forces.
Salt formation occurs when acidic substances directly interact with alumina, leading to the dissolution of alumina and the formation of salts.
Coordination interactions involve coordinate covalent bonds that share electrons and are considered strong interactions.
Hydrogen bonding occurs when materials capable of hydrogen bonding (H atom bonded to F, O, or N) directly interact with the oxygen atoms of alumina or silica gel.
Dipole-dipole interactions are indirect interactions and are a result of dipole polar-induced interactions. These interactions are the weakest among the important interactions.
Van der Waals forces are weak forces that involve nonpolar molecules and require extremely high molecular weights to bind strongly.
Please note that without knowledge of the specific content in the book, the details provided are based solely on the information you provided.