What are the phases used for the different types of chromatography?
Stationary Phase & Mobile phase...
Mobile phase can be considered as the solvent/phase that transports the sample.
Stationary phase is one that interacts with this mobile phase, depending on what is present in the sample... the mobile phase will make it's way through the stationary phase in a certain amount of time.
This time is called the retention time and is a unique characteristic for the sample being tested
Mobile phase can be considered as the solvent/phase that transports the sample.
Stationary phase is one that interacts with this mobile phase, depending on what is present in the sample... the mobile phase will make it's way through the stationary phase in a certain amount of time.
This time is called the retention time and is a unique characteristic for the sample being tested
Thanks
So the sample moves due to intermolecular forces with the mobile phase; and the mobile phase moves due to intermolecular forces with the solid phase? Can the sample also have intermolecular forces with the solid phase?
So the sample moves due to intermolecular forces with the mobile phase; and the mobile phase moves due to intermolecular forces with the solid phase? Can the sample also have intermolecular forces with the solid phase?
erm not quite
for example in GLC the sample moves due to pressure provided by the system... the stationary face itself slows it down due to interactions (such inter-molecular forces). So it does quite the opposite of what you said it kind of opposes the flow... imagine if the mobile phase could form hydrogen bonds with the stationary phase... then it would get slowed down quite a bit Hope that makes sense... and yes the stationary phase is usually solid I believe.
Anybody did alternative to practical, on 15th June...? there was a pretty bad NMR question.. we could expect something twisted like that in Unit 4 too right.. what do y'all think ? any resources to practice NMR ( other than pastpapers )...?
for example in GLC the sample moves due to pressure provided by the system... the stationary face itself slows it down due to interactions (such inter-molecular forces). So it does quite the opposite of what you said it kind of opposes the flow... imagine if the mobile phase could form hydrogen bonds with the stationary phase... then it would get slowed down quite a bit Hope that makes sense... and yes the stationary phase is usually solid I believe.
hey.. can u explain to me what happens to the solubility of aldehydes and ketones in water, when the length of chain increases?
Can anyone please help me..in jan 2013 q19 c i) in the data given its said that X is a neutral organic compound..the marking scheme says it means its not a carboxylic acid..i dont seem to understand this :/ can someone explain this?
Can anyone please help me..in jan 2013 q19 c i) in the data given its said that X is a neutral organic compound..the marking scheme says it means its not a carboxylic acid..i dont seem to understand this :/ can someone explain this?
Can anyone please help me..in jan 2013 q19 c i) in the data given its said that X is a neutral organic compound..the marking scheme says it means its not a carboxylic acid..i dont seem to understand this :/ can someone explain this?
Well I would think Carboxylic acid is not neutral because it dissociates quite a bit... the H+ is easily liberated and it's pH will be fairly low.
I think I did ethanol for that one in January, pH must be around 7
God damn it, I hated this paper so much
Ohh okay. But the third point says that its either a primary or secondary alcohols, so cant they dissociate to give OH-?? I feel dumb for not knowing these things -.-
Ohh okay. But the third point says that its either a primary or secondary alcohols, so cant they dissociate to give OH-?? I feel dumb for not knowing these things -.-
I think the bond is strong covalent therefore it does not dissociate, I've also never heard of alcohols being a base, but it's a good question... & first time I've had to think about that
I think the bond is strong covalent therefore it does not dissociate, I've also never heard of alcohols being a base, but it's a good question... & first time I've had to think about that
So carboxylic acids have the same OH bond, the one that gives away H+ like you and the mark scheme said. So why cant alcohols give away H+? And yes m sure alcohols arent bases too. Feel stupid for asking that now.. anyway.