Colloidal kinetics question?

[T.Ryan]

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I want to make sure I have the right handle on this. Fick's law relates to dispersING solids, whereas Einstein's law of diffusion indicates disperSED particles, Stoke's law illustrates sedimentation and

D=kT/6πηNa=RT/6πηaN

is the overall equation relating all of the above to indicate an AVERAGE diffusion rate including when it's still mostly in the solid stage, while dispersing and while sedimentation is taking place?

Is this correct?

 

[MountainPharmD]

Not the place for those types of questions...ask someone in your class or your professor......

 

[bananaface]

We have allowed these sorts of questions (from current students) here in the past. It's not as if it is a "do my homework for me" type thing.

 

[MountainPharmD]

Good for you for allowing these questions in the past. I do not believe this is the place to ask questions about your homework. Perhaps a subforum is necessary?

 

[njac]

I figured you meant "not the place for these questions" because you will never use it again. Unless you go into pharmaceutics. I don't miss pharmaceutics.

 

[T.Ryan]

I thought this place was for people who are actually in training, hence the 'STUDENT' network? Surely while you're in training you should be concerned with the material you're learning?
If not, do you know of any alternative forums where I could pose this question?
Thank you for your time!

 

[MountainPharmD]

Come on Mods where ya at??????? We have subforums for pre-pharmacy, PCAT, licensure and exams, and residencies and fellowships. How about a subforum for homework and kinetics questions. Call it the kinetics and homework forum: For topics related to kinetics, pharmaceutics, and pharmacy homework.

 

[MountainPharmD]

I thought this place was for people who are actually in training, hence the 'STUDENT' network? Surely while you're in training you should be concerned with the material you're learning?
If not, do you know of any alternative forums where I could pose this question?
Thank you for your time!

I gave you an alternative forum....Your clasmates or your professor.....

 

[T.Ryan]

I'm going ahead in the classwork, since I'm doing a scholarship exam at Easter. We haven't covered this yet. The professor giving this class is retiring this year and it seems the new professor hasn't prepared for it yet.

Sorry. I won't post questions regarding pharmacy school material again.

P.S- By forums I meant forums outside the SDN network. Or are we not allowed to ask for help anywhere on the internet?

 

[sdn1977]

I'm going ahead in the classwork, since I'm doing a scholarship exam at Easter. We haven't covered this yet. The professor giving this class is retiring this year and it seems the new professor hasn't prepared for it yet.

Sorry. I won't post questions regarding pharmacy school material again.

P.S- By forums I meant forums outside the SDN network. Or are we not allowed to ask for help anywhere on the internet?

paperclip - you already posted this same question on the Physics forum, so you know there are other forums out there.

Personally, I know Ficks law & Stokes-Einsteins law of diffusion in a very general sense and I cannot derive what you are looking for. I believe that would be a question more appropriate to someone who is in a PhD course in chemistry. Obviously, the folks on the Physics forum didn't answer your question.

I do know that Ficks law can be applied to glass, which is technically a liquid. But, Ficks law 1 is applied to steady state when the concentration in the volume doesn't change. Ficks law 2 is applied to a non-steady state with continually changing diffusions. Einstein's law describes molecular movement in a liquid or a gas when particles move independently of each other. Stokes law describes spherical particle movement only, I think.

Your extrapolation of these equations to describe an AVERAGE diffusion rate is beyond what I know or have the ability to do. However, when I think of colloidal dispersions, I'm not sure there is an average law which describes them as a group, but there might be one which would describe them individually.

Good luck with your work. I think you have plenty of time between now & Easter (6 months?) to pursue the topic with the new professor. But - I'm curious, if you've not covered this yet, why pose the question? Perhaps after being presented with the material in a cohesive fashion, it will become clear.....

 

[bananaface]

Come on Mods where ya at??????? We have subforums for pre-pharmacy, PCAT, licensure and exams, and residencies and fellowships. How about a subforum for homework and kinetics questions. Call it the kinetics and homework forum: For topics related to kinetics, pharmaceutics, and pharmacy homework.

There is not probably enough interest to support a general study concepts subforum. A homework-oriented area has been requested in the past and declined because of plagurism potential.

Pharmacy is a board for topics of interest to current students and practitioners. Some students like to run concepts by others to improve their understanding and to facilitate the learning process. If you don't care for a topic someone else presents, you don't have to participate in their thread.

Please allow this thread to get back on track.

 

[MountainPharmD]

paperclip - you already posted this same question on the Physics forum, so you know there are other forums out there.

Personally, I know Ficks law & Stokes-Einsteins law of diffusion in a very general sense and I cannot derive what you are looking for. I believe that would be a question more appropriate to someone who is in a PhD course in chemistry. Obviously, the folks on the Physics forum didn't answer your question.

I do know that Ficks law can be applied to glass, which is technically a liquid. But, Ficks law 1 is applied to steady state when the concentration in the volume doesn't change. Ficks law 2 is applied to a non-steady state with continually changing diffusions. Einstein's law describes molecular movement in a liquid or a gas when particles move independently of each other. Stokes law describes spherical particle movement only, I think.

Your extrapolation of these equations to describe an AVERAGE diffusion rate is beyond what I know or have the ability to do. However, when I think of colloidal dispersions, I'm not sure there is an average law which describes them as a group, but there might be one which would describe them individually.

Good luck with your work. I think you have plenty of time between now & Easter (6 months?) to pursue the topic with the new professor. But - I'm curious, if you've not covered this yet, why pose the question? Perhaps after being presented with the material in a cohesive fashion, it will become clear.....

sdn1977 you rock! I am puzzled by one thing though....You know there is a physics forum and you participate?!?!? Now you are starting to scare me.

paperclip - you already posted this same question on the Physics forum, so you know there are other forums out there......

 

[sdn1977]

sdn1977 you rock! I am puzzled by one thing though....You know there is a physics forum and you participate?!?!? Now you are starting to scare me.

no I don't! I don't know this stuff, but its easy to find someone who is just "skimming" forums......

The physics forum has a homework/help thread which my kids used - that was a logical place to look & paperclip is not too creative in how he/she words his/her questions.

 

[MountainPharmD]

no I don't! I don't know this stuff, but its easy to find someone who is just "skimming" forums......

The physics forum has a homework/help thread which my kids used - that was a logical place to look & paperclip is not too creative in how he/she words his/her questions.

Oh sure! I am going to check. You are probably a regular on the physics forum. Let me guess physics1977 is your screen name. I am going to check...BRB!!

 

[sdn1977]

Oh sure! I am going to check. You are probably a regular on the physics forum. Let me guess physics1977 is your screen name. I am going to check...BRB!!

Are you still looking????

Nope - you won't find me there. That was always the laugh around our dinner table. I remembered the calculus & obviously, chemistry.....so I could help the kids with those subjects. But drsdn, who took all the same stuff (he was a biochemist in a previous life, for gosh sakes!) - claims he didn't remember any of it. I think he did that to get out of helping, but he could help write a history paper like nobody else & he is d*mn good with plaster of paris & sugar cubes.

But, when those physics questions would come up - you know the kind...where wil the flea end up if he is crawling at 0.2 feet per hr east on the back of the dog who is sitting in a boat which has left the dock at a 32 degree angle heading northwest on a river flowing at 27 miles per hr and is 0.75 miles wide?

Suddenly, drsdn got all smart🙂 & he could help them. Its a good thing too because I always got stuck on the whole "why does the d*mn dog have fleas in the first place!😀 I did not like physics much but I could do what was required, but not much more.

So.....keep lookin'.....you won't find me there. I do have a sister-in-law who got a masters in mathematics.....I wonder if she's there....

But - see.....now we've given these students a place to go for physics help - not a bad thread at all😛

 

[T.Ryan]

The physics forum was great during last year, but no one is answering this question! I think they somehow know that you all disapprove of it. 😛

I'm sorry, but everyone had to deal with this at some point, the sooner we finish up with all this stuff that we'll never use again, the better- no point in getting stuck at something like this, I could be using my time more wisely learning things more relevant to being a pharmacist. Unfortunately, this class does need to be passed. 😀

And, yes, I'm not very creative- I'm not a physics type, writing this out once was painful, I don't want to have to reword the whole thing again!

 

[All4MyDaughter]

Its a good thing too because I always got stuck on the whole "why does the d*mn dog have fleas in the first place!😀

At our house the dog has fleas because Mr. A4MD thought he put the Frontline on the dog but actually left it sitting on the back of the toilet where it sat for three days until A4MD got home from pharmacy school and finally put it on the dog, hopefully eradicating the damn fleas. 😡