Does methylated spirits conduct electricity?

Question

does methylated spirits conduct electricity when it is by itself or does it need water to make it able to conduct electricity?

if it does conduct electricity either by itself or with water is it a good conductor?

Answer 1

It will not be a good conductor.  The reason nonmetallic liquids conduct electricity is due to electrolytes.  Electrolytes are ions that are free to move in the solution, and in doing so, can move charge from one electrode to another.

You probably know that saltwater conducts electricity better than plain water.  This is because the sodium and chloride ions will migrate to the electrodes when a voltage is applied (sodium to - and chloride to +).  The chloride ions will lose electrons to the electrode to form chlorine gas, while the sodium ions will gain electrons from the other electrode to form sodium metal (which immediately reacts with the water to form hydrogen gas and sodium and hydroxide ions).  In this way, a current flows through the solution.

Pure water is actually a pretty bad conductor.  Ordinary water contains traces of sodium, magnesium, calcium, chloride, sulfate, and other ions that act as electrolytes.  When these are removed, the only ions that are present are those that come from the autoionization of water (the formation of H+ and OH- ions - if you have learned about pH, you will know about this).

Methylated spirits are mixtures of ethanol and methanol.  Water has an acid dissociation constant of 1x10^-14.  In contrast, the Ka for ethanol is only 1.26x10^-16, while that for methanol is 3.16x10^-16.  These are about 100 times less than those for water, so there will be fewer ions present in solution, and less conductivity.

Mixing with water will increase the number of ions, and thus conductivity, but the solution will still not be a good conductor.  You might have luck by dissolving ionic salts in the methylated spirits: these will act as electrolytes and increase the conductivity.  I am not sure which salts will dissolve well; this depends in part on the mixture of ethanol, methanol, and other denaturants used.