[mgws87]

I received this question and I have no idea where to begin!

10.0ml of an unknown sample of Ni²+ gave a current of 2.36 μA. After 0.500ml  solution of 0.0287 Molar Ni²+ was added to the 10.0ml sample, the current increased to 3.79 μA. What is the concentration of Ni²+ in the sample?

Any help would be appreciated!

Thanks

[Borek]

Nothing to do with gravimetry, some polarographic method it is.

Assume that current is directly proportional to concentration.