# Homework Help: Current in cell during a certain period

1. Feb 18, 2006

### eagle63903

Does anyone know how to do this problem? I cannot find any examples in my book like it, and I have gotten no where in a full hour.

If 3.9x10^-3 of gold is deposited on the negative electrode of an electrolytic cell in a period of 2.67 h, what is the current in the cell during this period? Assume that the gold ions carry one elementary unit of positive charge.

Round your answer to three significant figures. The molar mass of gold is 197g/mol Avogadro's number is 6.022x10^23 atoms/mol The elementary change is 1.6x10^-19 C.

Any help would be appriciated, especially a step by step analysis if you could.

Thanks
eagle63903

2. Feb 18, 2006

### nrqed

You have to break up the solution in two steps.

First step: if you know the mass of gold that was deposited, you should be able to calculate the actual number of gold atoms that were deposited (this is where the molar mass and Avogadro`s number comes into play). Do you know how to do that? (no need to worry about charge or current in that step)

Second step: once you know the number of atoms that were deposited, you know the total charge that was transferred and you use I=charge/(time interval)

Pat