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Q & A: ionic conduction

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Most recent answer: 02/26/2015
Q:
Which is a molecular substance whose water solution conducts electricity?
- jonathan (age 17)
Tomball, TX, USA
A:

Any molecule that tends to form ions, electrically charged parts, when it goes into solution will help conduct electricity. That's because the electric field will drag the positive ions one way and the negative ions the other way. Many molecules do this. For example acetic acid (in vinegar) gives off an H+ , leaving an Ac-. All molecular acids do something like this. Bases also ionize, giving off an OH- and leaving a positive ion. Salts, like sodium acetate, fall apart into other ions: Na+ and Ac-.  

Some of the most familiar salts, however, like NaCl, are crystals and not molecular. A molecule is a specific arrangement of a specific number of atoms.  A crystal, in contrast, is a patterned arrangement of atoms that can extend to arbitrarily large numbers. NaCl is found not as a bunch of separate NaCl's but rather as extended crystals.

Mike W.


(published on 02/26/2015)

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