Fairly basic Galvanic Cells question (1 Viewer)

[ChopperT]

In a galvanic cell, if you have two electrodes in the same beaker, would they register a voltage if that beaker contained sea water? Or tap water? Or distilled water? or rain water?

 

[bachviete]

In a galvanic cell, if you have two electrodes in the same beaker, would they register a voltage if that beaker contained sea water? Or tap water? Or distilled water? or rain water?

A voltage will register if there is a current. There is a current when there is a full path. H2O does not in fact conduct electricity, this is because it is a molecule and taking away electrons would be difficult. But when it combines with other elements we get a solution which is conductive.

See if you can figure the rest out.

 

[ChopperT]

A voltage will register if there is a current. There is a current when there is a full path. H2O does not in fact conduct electricity, this is because it is a molecule and taking away electrons would be difficult. But when it combines with other elements we get a solution which is conductive.

See if you can figure the rest out.

so it would conduct in sea water because that contains NaCl?

 

[iRuler]

Thats Right.

 

[ChopperT]

but what about rain water? Doesnt that often contains sulfates or nitrates?

 

[jennaaa]

I'm not sure if this is correct or not, simply hypothesising but... if the electrodes are in the one beaker wouldn't there be no voltage register on the meter as even if the circuit was completed with wires etc, the electrons would just take a short cut and flow within solution? Isn't that the point of having two half cells?

Edit: Sorry, kinda off track what you were asking about the sea water.

 

[iRuler]

but what about rain water? Doesnt that often contains sulfates or nitrates?

Yes it does, but not always, and doesnt have to be everywhere, mainly in highly industrialised places... unless it gets blown away.

I'm not sure if this is correct or not, simply hypothesising but... if the electrodes are in the one beaker wouldn't there be no voltage register on the meter as even if the circuit was completed with wires etc, the electrons would just take a short cut and flow within solution? Isn't that the point of having two half cells?

This is also correct.

 

[ilikebeeef]

It's not the water that conducts electricity, but any ions within it do.

 

[adomad]

It's not the water that conducts electricity, but any ions within it do.

water conducts a negligible amount of electricity (pure water) as there is very little ion formation...10^-14.. but yeah, you need ions or electrolytes to make a current flow

 

[ilikebeeef]

water conducts a negligible amount of electricity (pure water) as there is very little ion formation...10^-14.. but yeah, you need ions or electrolytes to make a current flow

Yeah. By water I meant H2O lol. Not OH- and H+ which forms in concentrations of 10^-14 mol/L.