Science Buddies: "Ask an Expert"

I am a student of 12 grade and I need to prepare an investigatory project in physics for my exams.

My teacher has suggested me to make a project on electrical conductance of different liquid solutions, like milk, fruit juices, etc.

It would be geat if you can tell me what should I specifically do, like whether I should find the e.m.f produced by cells using diffeent liquids as electrolytes, or should I check the resistance of the solutions, or if you can suggest something better which would make this project more interesting and different from the other projects.

I would really be greatful if you can help me out .

thanks

Have you learned about conductance (what it means, etc)? Basically, it's how "easily" the solution conducts electricity, or how easily electrons flow through the medium. Have you learned about Ohm's law v=ir?

Recall that resistance is how "difficult" it is for electrons to flow through a medium, which is kinda like the opposite of conductance (think inverse). Am I making sense? Soooo, you can pretend that your solution is one giant resistor, and if you can measure the voltage drop across the two ends (the terminals, which is indicated by a + and a -) and the current that flows through, then you can measure resistance, and hence conductance.

Check out these sites:

http://jchemed.chem.wisc.edu/JCESoft/CC ... 1R3230.HTM

http://seps.mgd-colo.peak.org/oracle/or ... 26928.html

http://www.iit.edu/~smile/ph8913.html

http://www.instant-essays.com/physics/e ... ytes.shtml

Do a google search for more information.

Shijun