Electrolysis

[bigquestion]

Why does the mass of a substance obtained icreasewith current?

[gen2]

Metals in the ionic state are positively charged. In order to deposit as metal (electro-plating) each ion must receive sufficient electrons to neutralise its charge.

eg. Cu++ plus 2 electrons = Cu(solid)

A current is the flow of electrons, so:

More current = more ions neutralised = more metal deposited.

[brachiopod]

You have forgotten a variable.

I could obtain more mass of metal with 0.1mA than you could with 1 MA of current.

Do you know how?

[bigquestion]

How?

[brachiopod]

*sorry* ignore me, drunk again.....

[brachiopod]

Sorry, didn't expect an answer so quick!

Time of course. If this is assesed work, you have to qualify the rate at which the electrolytic product is obtained.

It's not meant to be pedantic, but I could obtain the same mass with micro-amps that I could with Mega-amps - it's just that it would take hell of a lot longer! It's these little (obvious) qualifiers that get extra marks !!

[Gef]

The mass of metal deposited (or gas produced) depends on the quantity of charge (Q) passed through the electrolyte.

Q = I t and so it depends on both the current (I) and the time (t).