can polar molecules conduct electricity (0 net charge)?

[sangria1986]

Ok so I know that strong and weak electrolytes can conduct electricity including salts and strong/weak acids and bases...

but what about water and other non ionic compounds...water too can conduct electricity correct? Because its polar... Or am i wrong?

If water can conduct electricity because its polar does that mean all polar molecules can?

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[Rabolisk]

Pure water is not considered a conductor. Conductors are typically any material in which charge carriers are free to move about. Salts and strong acids/bases in aqueous solutions, as well as metals are generally considered good conductors. Most nonmetals are not good conductors, as a general rule.

 

[Prateek]

Pure water is not considered a conductor. Conductors are typically any material in which charge carriers are free to move about. Salts and strong acids/bases in aqueous solutions, as well as metals are generally considered good conductors. Most nonmetals are not good conductors, as a general rule.

Wouldn't water undergo self-ionization though to form H3O+ and OH- ? Thus making it a good conductor?

 

[Rabolisk]

Wouldn't water undergo self-ionization though to form H3O+ and OH- ? Thus making it a good conductor?

No. Water does conduct better than glass or diamond, but is considered to have a low electrical conductivity, because it only ionizes to a small extent.

 

[sangria1986]

No. Water does conduct better than glass or diamond, but is considered to have a low electrical conductivity, because it only ionizes to a small extent.

so basically polarity of a molecule has nothing to do with its conductivity?

Thus the only reason water conducts electricity based off its polarity is because its polarity allows it to dissolve ionic compounds.

Would it be fair to say that polar solvents then can conduct electricity in the presence of strong electrolytes?

Also...would the converse be true, that nonpolar solvents are poor at conducting in the presence of strong electrolytes?

Im just trying to come up with trick questions that test my knowledge.

My guess for above is that water can conduct only in presence of electrlytes and this applies to most polar solvents and nonpolar solvents dont conduct electricity.

 

[sangria1986]

what about colloids? they have a net charge of zero but move towards electric sources because their outer layer is charged....can colloids conduct electricity?

also, would salts in nonpolar solvents be considered colloids? Im assuming the salts just aggregate. or do they precipitate instead of aggregating in solution?

 

[AcclratngCharge]

what about colloids? they have a net charge of zero but move towards electric sources because their outer layer is charged....can colloids conduct electricity?

also, would salts in nonpolar solvents be considered colloids? Im assuming the salts just aggregate. or do they precipitate instead of aggregating in solution?

Are you seriously trying to figure out questions like this? They will NOT be on the mcat. Have you ever heard of a colloid conducting electricity?

For the MCAT:
Colloids are not solutions
Particles can be 'filtered' by dialysis only
Tyndall effect
Coagulation by heating or adding electrolyte

Salt in nonpolar solvent is NOT a colloid, colloid is called colloid because of SIZE

Obviously there are exceptions to what is above, but not on the MCAT.

 

[sangria1986]

Are you seriously trying to figure out questions like this? They will NOT be on the mcat. Have you ever heard of a colloid conducting electricity?

For the MCAT:
Colloids are not solutions
Particles can be 'filtered' by dialysis only
Tyndall effect
Coagulation by heating or adding electrolyte

Salt in nonpolar solvent is NOT a colloid, colloid is called colloid because of SIZE

Obviously there are exceptions to what is above, but not on the MCAT.

lol I'm brainstorming trick questions possible.

 

[Rabolisk]

95% of mcat questions are straightforward, and easily answerable if you have a solid background knowledge.

 

[lorenzomicron]

Polarity is the property of entire molecules.
Conductivity is the property of dissolved molecules, which may or may not become ionic (strong or weak) in solution.
Non-electrolytes including the entire class of non-polar molecules does not conduct electricity.
Electricity is the flow of electrons or charge, i.e. the net flow. Thus, for instance, colloids which are composed of non-electrolytes will not conduct electricity because they would not dissolve to the extent that they are able to be free moving charge.

Do not confused electrical conduction (i=dq/dt), the flow of charge, with electrical properties such as polarity, dipole moment, etc.