[abrahamsaynes]

i got problems with this Icho, I dont understand how the faraday is calculated, the doubt is marked in the word file. :

[Borek]

Please do something about these images - they are huge, yet the important part is pretty small. Reading the problem is annoyingly difficult.

Reading forum rules wouldn't hurt as well, you will have much better chances of receiving help if you will explain what it is that you don't understand.

[Arkcon]

I'd like to welcome you, abrahamsaynes: to the Chemical Forums.  According to the Forum Rules{click}, we want to see your attempt, so please click on that link, read the contents, and comply with our rules, so we can help you. 

We'd like to help, but I really don't understand what the problem is that you're having.  The problem has a complete working, so I don't know what you're missing.  How would you calculate what is unknown?  Does your textbook provide a similar example?  What answer do you get when you plug in the numbers you have?  Is F a constant?  I'm asking, I don't really know.

[abrahamsaynes]

I'd like to welcome you, abrahamsaynes: to the Chemical Forums.  According to the Forum Rules{click}, we want to see your attempt, so please click on that link, read the contents, and comply with our rules, so we can help you. 

We'd like to help, but I really don't understand what the problem is that you're having.  The problem has a complete working, so I don't know what you're missing.  How would you calculate what is unknown?  Does your textbook provide a similar example?  What answer do you get when you plug in the numbers you have?  Is F a constant?  I'm asking, I don't really know.

First thanks for answering and attending my question, my doubt is that i dont know how is calculated that part that is highlighted, it doesnt show any formula or something like that.
I dont know how the 40.575 mF are gotten or the 1087.4 mAh. Did i explain correctly, I dont speak so much English.

[mjc123]

It's not very clear, it does rather jump ahead without showing working.
How much charge is passed, at the given current for the given time? How many faradays does this correspond to?
How much charge would be used if you were using the whole of the initial solution, rather than just the sample indicated?
Given the stated efficiency, how much charge would be actually used to deposit all the metals in the alloy sample?
(I assume you know how to convert coulombs to faradays and mAh.)

[abrahamsaynes]

It's not very clear, it does rather jump ahead without showing working.
How much charge is passed, at the given current for the given time? How many faradays does this correspond to?
How much charge would be used if you were using the whole of the initial solution, rather than just the sample indicated?
Given the stated efficiency, how much charge would be actually used to deposit all the metals in the alloy sample?
(I assume you know how to convert coulombs to faradays and mAh.)

Hahahahaha yeah