# Magnetic Susceptibility of a Solution

 P: 2 Hi! I'm trying to calculated the magnetic susceptibility of a solution. I am using this table to know what the susceptibility of each substance is. In other words, I want to know how the magnetic susceptibilities of two (or more) substances add up once they are mixed together into a solution. I am not sure how this works, whether it is a simple weighted sum depending on the concentration of each individual substance, or whether it is (as I suspect) much more complex than that. Thank you for your help and your time!!
P: 1,115
 Quote by Sebolains Hi! I'm trying to calculated the magnetic susceptibility of a solution. I am using this table to know what the susceptibility of each substance is. In other words, I want to know how the magnetic susceptibilities of two (or more) substances add up once they are mixed together into a solution. I am not sure how this works, whether it is a simple weighted sum depending on the concentration of each individual substance, or whether is it (as I suspect) much more complex than that.
I have no experience with that procedure, but here's a 'common sense' opinion, given the generally feeble magnetic properties expected of solutions of diamagnetic/paramagnetic chemicals. On the assumption there are no strong chemical reactions in solution, it should be just a weighted sum - due allowance being made for any demagnetizing factor present in the sample container geometry: see e.g. http://www.google.com.au/url?sa=t&rc...etukzw&cad=rja (from around last quarter of article). For diamagnetic or paramagnetic solutions the demagnetizing field should typically be a very small perturbation to the applied field, but it depends on how accuate you need to be. If your concern is with possible chemical interactions, sorry can't help.
 P: 2 Yes, I'm looking for just a solution where there is no chemical reactions occurring in it. I didn't think of that when I posted my question, but I am not looking for something that complex. So you're saying it should just be a weighted sum of their volume susceptibilities using their volume proportions as the weight?
P: 1,115
Magnetic Susceptibility of a Solution

 Quote by Sebolains Yes, I'm looking for just a solution where there is no chemical reactions occurring in it. I didn't think of that when I posted my question, but I am not looking for something that complex. So you're saying it should just be a weighted sum of their volume susceptibilities using their volume proportions as the weight?
I see no real problem doing it that way. Whether or not solutions are dilute, magnetic susceptibilities are so low everything is effectively linear to a very good approximation even for high applied field, which is probably not even the case. The one problem I can think of is assuming you are using an AC method (RF frequencies or above). There just may be significant magnetic coupling to molecular orientation. Might then have to watch out for resonance effects re molecular rotation depending on frequency range. Highly unlikely for diamagnetic material but possible in paramagnetic case, but honestly not at all sure and if in doubt seek expert advice. Maybe CRC handbook has such data.