Chemistry question please!

Question

101)

Silver can be electroplated at the cathode of an electrolysis cell by the following half reaction.

Ag (aq) e- ---> Ag(s)

How many moles of electrons are required to electroplate 5.8 g of Ag?

??????

Please explain so I can understand in the future. :)

thanks!

Answer 1

Since the reaction goes from Ag+  -->  Ag 0 there is one electron needed for each silver ion. So just figure out how many moles of Ag you have.  5.8 g Ag / 107.868 g Ag per mole = 0.05377 mole of electrons. Notice g Ag on top is cancelled by g Ag on bottom, so only mole is left.  ie    5.8 g Ag //107.868 g Ag / mole.  That is 0.05377 X

6,02 X 10^23 electrons.

Answer 2

Atomic mass of Ag is 107.8682 gm per mole

Ag ion has just one positive charge

So you will need 5.8/107.8682 = 0.052 moles electrons