Galvanic cell question (1 Viewer)

[enigma_1]

Is it true that when more reactive metals are used in a galvanic cell, a greater voltage is produced?

EG like Magnesium and zinc would produce higher voltage than Copper and Silver?

if not then what produces a greater voltage?

Cheers

 

[strawberrye]

If you look at the HSC electric potential table, which lists elements reduction with increasing reduction potentials-i.e. more positive as you go down the table, you see there are three elements/compounds between magnesium and zinc, while there are about 5 element/compound between copper and silver-essentially more reactive metals when used in a galvanic cell does not produce greater voltage, but rather the further spaced the metals are on the reduction potential-the greater the difference of their reduction potential-which will increase their tendency to donate or accept ions respectively, the higher the voltage of a galvanic cell-which essentially refers to the transfer of electrons in the external electric circuit, to illustrate this point further, say two very reactive metals, sodium-placed in water, will burst it into fire, and magnesium-readily burns with spark into a white powder-the first has a reduction potential value of -2.71V, but the second has reduction of -2.36V, so magnesium will be reduced and sodium oxidised, giving only 0.35V-which is a lot lower than your less reactive(the two metals comparative) combinations above, it is the difference in reactivity that matters, not the reactivity of the metals itself
Any more questions about chemistry, feel free to pm me hope this helps

 

[anomalousdecay]

E(cathode) - E(Anode) from the table. To achieve the greatest possible potential, the two electrodes must be furthest away on the chart (standard reduction potentials) from each other. This can be proved by simple maths work.