HOw to calculate the number of electrons from a given battery capacity

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Clark Kent
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Homework Statement



If the cell capacity of a cell is 3,5A.h; calculate the number of electrons that flow through the cell in 30 minutes.


Homework Equations


Q= I.t


The Attempt at a Solution


Q= I.t
= 3.5x(1800)
= 6300C

6300/(1.6 x 10^-19)
= 3.94 x 10^22 electrons
 
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well, one definition of the amp, although not the right one, is that 6x10^18 (forgive me if my numbers are wrong because i don't have a calc right now, but you can get this number from the elementary charge e) flow through in unit time (1s).
If capacity is 3.5Ah, then convert the 30 minutes to hours, multiply that by 3.5Ah, and then use the relationship q=Ix(change in time).
However a better way to do this would be to convert the minutes into seconds, as well as 3.5Ah to As(ampere seconds) and then do the calculation.