In my chemistry homework there is a question on conductivity that I don't understand, can anybody help?
'Solid calcium chloride does not conduct electricity. An aqueous solution of calcium chloride does conduct.
Explain the different conductivities of solid and aqueous calcium chloride.'
It's asking why solid CaCl2 won't conduct electricity, but when dissolved in water it will. Why do you think that is?
Think about the arrangement of ions in solid calcium chloride and the ions in a solution of calcium chloride.
In solid calcium chloride the atoms are arranged in a lattice structure, similar to that of sodium chloride. The atoms are in fixed positions and so cannot move to carry charge throughout the structure, which is what electrical conductivity is.
In aqueous calcium chloride the atoms are not in fixed positions and therefore can move and carry charge.
Is it because the ions are free to move through the water allowing them to carry charge (like free electrons in a metallic substance)?
EDIT: Posted this before I saw motoe's post, woops!
Thanks for your help.
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