How much time in hours would it take to play out 42.1 grams of nickel using a current of 3.08 amps. So here we have one mole of nickel 2 plus ion reacting with two moles of electrons to give us one mole of nickel solid. Here we're going to start out with grams of given 42.1 grams of nickel, and we're going to change those grams of giving it to moles of given grams go on the bottom so they can cancel out. One mole of nickel goes on top here.

If we look at the periodic table, we'll find the atomic mass of nickel that comes out to 58.693. We now have moles of given. So next step is to get moles of electrons of given. To do that, we look at the coefficients in the balanced equation. Wherever one mole of nickel solid, there's two moles of electrons involved. So for every one mole of nickel, there's two moles of electrons. So moles of nickel are gone.

Now we need to go from moles of electrons of given to charge of unknown. We do this by utilizing faradays constant. So for every one mole of electrons it's 96,045 coulomb's. Now that we have charge of unknown we can find here. Let's see from this we can utilize our current and that'll help me find seconds involved. Remember amps is equal to 3.08 here coulombs per second. So we put the 3.08 coulombs on the bottom, one second on the top.

We have seconds now. So now it just becomes converting seconds into minutes and then into hours. So we're going to say we have 60 seconds for everyone minute we have here. One hour is equal to 60 minutes. Everything here cancels out, so at the end we're going to get 12.483 hours. Here are numbers in the question. Have three sig figs so I'm going to round this to 12.5 hours O this would be our final answer.